Healthy People Statistical Notes - Number 27 - CDC

 
Healthy People Statistical Notes
  Number 27                                                                                                                February 2016

Measuring Progress Toward Target Attainment
and the Elimination of Health Disparities in
Healthy People 2020
by Makram Talih, Ph.D.; and David T. Huang, Ph.D., M.P.H., C.P.H., Office of Analysis and Epidemiology

    Abstract
    Introduction—Healthy People is                  “absolute value of the percent change       both absolute and relative measures of
    an initiative of the U.S. Department            from baseline” is used to measure           overall disparity: a) the simple difference
    of Health and Human Services that               movement. In addition, unlike in            between the highest and lowest rates,
    provides science-based, 10-year national        HP2010, both the extent of the movement     irrespective of intermediate rates; b) the
    objectives for improving the health             and its statistical significance (when      ratio between the highest and lowest
    of all Americans. As in the previous            measures of variability are available)      rates, irrespective of intermediate rates;
    three decades, Healthy People 2020              are used to determine progress status in    c) and a summary rate ratio between the
    (HP2020) has established overarching            HP2020 (e.g., “improving,” “little or no    best group rate and the average rate for
    goals and objectives, and is monitoring         detectable change,” or “getting worse”).    all other groups in a population domain.
    progress toward the attainment of its                                                       For objectives expressed in terms of
                                                    Comparisons to the best group rate—
    targets as well as the elimination of                                                       adverse outcomes, the HP2010 “index
                                                    As in HP2010, all groups composing
    health disparities among population                                                         of disparity” is obtained by subtracting 1
                                                    a population domain (e.g., race and
    groups. This Statistical Note discusses                                                     from the HP2020 summary rate ratio and
                                                    ethnicity, education, or income) are
    the HP2020 measurement practices,                                                           multiplying by 100.
                                                    compared to the group with the “best”
    contrasting them with those that were in
                                                    (i.e., most favorable or least adverse)     Conclusion—The multipronged
    place in Healthy People 2010 (HP2010)
                                                    rate. However, HP2020 uses the ratio        approach to measurement in HP2020
    and highlighting their strengths and
                                                    instead of the percent difference           addresses some of the complex
    limitations.
                                                    between the rates. In addition, HP2020      methodological issues and limitations
    Objective—This Statistical Note                 objectives that are expressed in terms of   identified in the past decade as well as
    documents the HP2020 methodology                favorable outcomes to be increased no       elsewhere in the literature.
    for measuring progress toward target            longer need to be re-expressed using the
    attainment and the elimination of health        complementary adverse outcomes for
    disparities, with a particular focus on         comparisons to the best group rate.         Keywords: Healthy People objectives •
    methodological considerations for the                                                       measurement • population subgroups •
                                                    Measures of overall health disparity—
    interpretation of findings.                                                                 health equity
                                                    In addition to detailed comparisons to
    Progress toward target attainment—              the best group rate, HP2020 provides
    For HP2020, the “percent of targeted            measures that quantify the degree of
    change achieved” still measures                 disparity overall across all groups
    movement of objectives that are moving          composing a population domain. Unlike
    from their baselines toward their targets.      in HP2010, where a single relative
    However, for objectives moving away             measure, the summary index, was used,
    from their baselines and targets, the           HP2020 uses three measures that include

                                   U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
                                                 Centers for Disease Control and Prevention
                                                      National Center for Health Statistics
Measurable objectives and targets
       Acknowledgments                                                  There are more than 1,200 objectives in HP2020 spanning
                                                                   42 topic areas, including just over 1,000 that were measurable
       The following individuals and teams have either             as of June 2015. Each measurable objective has a nationally
       contributed to the development of the Healthy People        representative data source, baseline value, and target for
       2020 (HP2020) measures presented in this report or          specific improvements to be achieved by the year 2020. A
       provided feedback that improved the presentation: Robert    few objectives have nationally representative data, yet they
       Francis, Jr. and the Health Promotion Statistics Branch
                                                                   are tracked only for informational purposes, so they do not
       (HPSB) programming team at NCHS; Jeffrey N. Pearcy
       and the HPSB research team; Carter R. Blakey, Deborah
                                                                   have 2020 targets. Just over 200 developmental objectives do
       Hoyer, and the Office of Disease Prevention and Health      not have baseline data, yet they have a potential data source
       Promotion’s Community Strategies Division at the            and are included in HP2020 to highlight their public health
       U.S. Department of Health and Human Services; and           importance and are expected to become measurable over the
       Rebecca Hines, Richard J. Klein, and Diane M. Makuc         course of the decade.
       (consultants).
                                                                        Prior to their potential inclusion in HP2020, objectives
                                                                   are drafted by subject matter experts from various federal
                                                                   agencies. The proposed objectives are made available for
                                                                   public comment and are reviewed by the Healthy People
Introduction                                                       Federal Interagency Workgroup. All objectives are approved
     This Statistical Note describes the Healthy People 2020       by HHS before being added to the HP2020 initiative.
(HP2020) methodology for measuring progress toward target               Whenever possible, targets for the HP2020 objectives are
attainment and the elimination of health disparities, with         set using science-based methods, such as:
a particular focus on methodological issues. The HP2020
                                                                    ● Modeling
measurement practices are contrasted with those in place for
the Healthy People 2010 (HP2010) decade; see Statistical            ● Projecting trends
Note No. 25, Measuring Progress in Healthy People 2010
                                                                    ● Knowledge of scientific findings and current interventions
(1), as well as the Healthy People 2010 midcourse and final
reviews (2,3).                                                          In the absence of adequate data, knowledge, or expertise,
     Healthy People is an initiative of the U.S. Department        HP2020 targets generally are set using a projected 10%
of Health and Human Services (HHS) that provides science-          improvement relative to their baseline values. On a case-by­
based, 10-year national objectives for improving the health        case basis, other target-setting methods are used as appropriate
of all Americans. For three decades, Healthy People has            (e.g., minimal statistical significance; total elimination;
established benchmarks and monitored progress over time to         maintaining baseline level; maintaining consistency with
“encourage collaborations across communities and sectors,          national programs, regulations, policies, or laws; or retention
empower individuals toward making informed health                  of HP2010 targets).
decisions, and measure impact of prevention activities”; see            Complete information about HP2020, including the
http://www.healthypeople.gov/2020/About-Healthy-People.            initiative’s history, its overarching goals, and objectives, is
Healthy People 2020, the fourth decade of the initiative, was      available from http://www.healthypeople.gov.
launched in December 2010.
                                                                   Population subgroups
Overarching goals
                                                                        Measurable HP2020 objectives that are population-based
       The four overarching goals established for HP2020 are to:   include data by demographic and socioeconomic categories,
    ● Attain high-quality, longer lives free of preventable        where available. For example, Table 1 shows HP2020
       disease, disability, injury, and premature death.           demographic and socioeconomic categories used to tabulate
                                                                   national data from the National Health Interview Survey
    ● Achieve health equity, eliminate disparities, and improve    (NHIS), which is the data source for over 100 measurable
       the health of all groups.                                   population-based HP2020 objectives.
    ● Create social and physical environments that promote             HP2020 strives for consistency in tracking population
       good health for all.                                        groups; however, population categories may vary by data
    ● Promote quality of life, healthy development, and healthy    source or by objective, due to survey design, data collection
       behaviors across all life stages.                           constraints, or other considerations. Therefore, HP2020
                                                                   population categories used to tabulate national data from data

2                                                                                                    Healthy People 2020 Statistical Notes
Table 1. Main population categories for HP2020 objectives from the National Health Interview Survey
                              Population categories                                                     Population categories

Total                                                                 Family income (percent of poverty threshold)
                                                                        Less than 100%
Sex                                                                     100%–199%
  Female                                                                200%–399%
  Male                                                                  400%–599%
Race and ethnicity                                                      600% and above
  American Indian or Alaska Native only                               Family type
  Asian only                                                            Single
  Native Hawaiian or Other Pacific Islander only                        Single parent with children
  Black or African American only                                        Married couple or partners
  White only                                                            Two parent family with children
  Two or more races                                                     Other
  Hispanic or Latino
  Not Hispanic or Latino                                              Country of birth
    Black or African American only, not Hispanic or Latino              United States
    White only, not Hispanic or Latino                                  Outside United States
Age group (years)                                                     Disability status
  Under 18                                                              Persons with activity limitations
    0–4                                                                 Persons without activity limitations
    5–11
    12–17                                                             Geographic location
  18–44                                                                 Metropolitan
    18–24                                                               Nonmetropolitan
    25–44                                                             Health insurance status (persons under age 65)
  45–64                                                                 Insured
    45–54                                                                 Private
    55–64                                                                 Public
  65 and over                                                           Uninsured
    65–74
    75–84                                                             Marital status (persons aged 18 and over)
    85 and over                                                        Married
                                                                       Cohabiting partner
Educational attainment (persons aged 25 and over)                      Divorced or separated
  Less than high school                                                Widowed
  High school                                                          Never married
  Some college
  Associate’s degree                                                  NOTE: Additional population categories may be added as needed.
  Four-year college degree                                            SOURCE: CDC/NCHS, HP2020 database.
  Advanced degree

sources other than NHIS may differ from those listed in                      options are new for HP2020 (e.g., country of birth, family
Table 1.                                                                     type, and marital status).
   HP2020 population categories differ from those used in                  Several population categories may be limited to persons
HP2010:                                                               of a specific age group (e.g., educational attainment, marital
                                                                      status, veteran status, and health insurance status). The age
  ● Education and income. Both education and income are
                                                                      groups that apply to these categories are specific to each
        included in HP2020 data tables when they are available.
                                                                      objective and may vary by data source. Caution must be
        In HP2010 data tables, only one of these variables
                                                                      used when comparing data for population categories that use
        typically was reported, even if the data source provided
                                                                      different age limits or when comparing to the total population.
        both. In addition, both education and income have a more
        granular disaggregation in HP2020 than that used in                Data may be either unavailable or not collected for
        HP2010.                                                       population categories not shown in the HP2020 data tables.
                                                                      However, if the data for a population subgroup have been
  ● New category options in HP2020. A number of options
                                                                      collected and analyzed but do not meet the criteria for
        have been added to data tables in HP2020. Whereas some
                                                                      statistical reliability, data quality, or confidentiality, the data
        of these options were included in HP2010 when data were
                                                                      are suppressed and marked accordingly in the data tables.
        available (e.g., age, disability status, health insurance
        status, geographic location, and sexual orientation), other       Detailed information about data suppression as well as
                                                                      additional considerations related to the demographic and

Healthy People 2020 Statistical Notes                                                                                                       3
socioeconomic categories used in HP2020 are forthcoming           need to make up the deficit from baseline in addition to the
from: http://www.cdc.gov/nchs/healthy_people/hp2020/              desired targeted change once the baseline value is regained.
hp2020_data_issues.htm.
                                                                       In HP2010, the amount and statistical significance of the
                                                                  “percent of targeted change achieved” were not considered
                                                                  in determining an objective’s progress status. For HP2020,
Multipronged Measure of Progress                                  both the extent of the movement and its statistical significance
Toward HP2020 Targets                                             (when measures of variability are available) are used to
                                                                  determine an objective’s progress status. Thus, in addition
     For HP2010 objectives that had at least two data points,     to HP2020 objectives where the values at baseline and most
the “percent of targeted change achieved” was used to             recent data points are equal, those objectives with available
quantify progress toward target attainment, unless the target     standard errors for which movement was not statistically
had been met or exceeded at baseline. The formula for the         significant, and those with no available standard errors for
“percent of targeted change achieved” was as follows:             which movement was less than 10%, are all qualified as
                                                                  having demonstrated “little or no detectable” change.
   Percent of     Most recent value – Baseline value
targeted change =                                    × 100.
    achieved       HP2010 target – Baseline value                 Classification of objective progress status
                                                                  in HP2020
     The “percent of targeted change achieved” expressed the
difference between the baseline and the most recent value as a         HP2020 objectives are classified according to the status
percent of the targeted change between the baseline and the       of their progress toward their targets or away from their
HP2010 target. The “percent of targeted change achieved”          baselines, as shown in Table 2.
was used to compare how much of the targeted change was
achieved for an objective relative to other HP2010 objectives.    Determination of objective progress status
For more information about the measurement of progress            in HP2020
toward target attainment in HP2010, see Appendix I.
     As learned in the Healthy People 2010 Final Review (3),      Objectives that met or exceeded their targets
there are various limitations to using the “percent of targeted    ● When the desired direction is increase, an objective has
change achieved” as the sole measure of progress toward
                                                                      met or exceeded its target at the most recent data point if
target attainment, some of which are listed here:
                                                                      most recent value ≥ HP2020 target.
    ● The “percent of targeted change achieved” is calculated
                                                                   ● When the desired direction is decrease, an objective has
      using only the target, baseline, and most recent data
                                                                      met or exceeded its target at the most recent data point if
      points. Fluctuations during the intervening years are not
                                                                      most recent value ≤ HP2020 target.
      considered.
                                                                        HP2020 objectives that met or exceeded their targets at
    ● The number of years between the baseline and most
                                                                  the most recent data point are designated by a TARGET MET
      recent data points might vary between objectives
                                                                  progress status indicator. Even though statistical significance,
      (e.g., data systems may have different data collection
                                                                  when measures of variability are available, is not factored into
      frequencies).
                                                                  the determination of the TARGET MET status, the movement
    ● Two objectives may be identical in their “percent of        is still evaluated for statistical significance; see Table 3 for an
      targeted change achieved,” even though they differ in the   example.
      amount of both the targeted and realized change from
      baseline.                                                   Objectives moving toward their targets
    ● Objectives moving away from their targets and those
      whose targets are exceeded at the baseline yield a          Direction
      negative “percent of targeted change achieved” value, and    ● When the desired direction is increase, an objective is
      these negative values are difficult to interpret.               moving toward its target at the most recent data point if
      For HP2020, the “percent of targeted change achieved”           baseline value < most recent value < HP2020 target.
still quantifies progress for objectives that are moving toward    ● When the desired direction is decrease, an objective is
their targets. However, for objectives moving away from               moving toward its target at the most recent data point if
their baselines and targets, the “absolute value of the percent       baseline value > most recent value > HP2020 target.
change from baseline” is used to measure movement. An
objective that moves away from its baseline and target would

4                                                                                                   Healthy People 2020 Statistical Notes
Extent of movement toward target                                   where SEt is the standard error at time t and SEb is the
                                                                   standard error at baseline.
     For HP2020 objectives that had not already met or
exceeded their targets at baseline, the “percent of targeted             Step 3. The RSE for the denominator, SDT , is calculated
change achieved” measures the extent of movement toward            as:
the target. It is given by:                                                                                      SEb
                                                                                               RSESDT =                     ,
   Percent of     Most recent value – Baseline value                                                          | RT – Rb |
targeted change =                                    × 100.
    achieved       HP2020 target – Baseline value                  because the target RT does not contribute to the variability of
                                                                   the targeted change; it is constant.
Statistical significance for objectives moving
                                                                        Step 4. An approximate RSE for the PQ is computed
toward, or meeting or exceeding their targets                      using a first-order Taylor series linearization of the variance of
     In HP2010, statistical significance of the “percent           the ratio of two random variables, with numerator and
of targeted change achieved” was not evaluated when                denominator RSEs, above:
measures of variability were available. Instead, the statistical
                                                                                                           2         2
significance of the simple difference “most recent value                                 RSEPQ =        RSESD t
                                                                                                                + RSESD T
                                                                                                                          .
– baseline value” was assessed to determine whether the
change from baseline to the most recent value was statistically
significant, irrespective of the target.                           Table 2. Classification of HP2020 objectives, by progress status

     In HP2020, statistical significance of the “percent                 Objective status                          Short explanation
of targeted change achieved” is evaluated using Taylor
                                                                   TARGET MET                     Target met or exceeded
linearization when measures of variability are available.
A one-sided 0.05-level test is used.                               IMPROVING                      Movement is toward the target and is either:
                                                                                                  – Statistically significant when measures of
     When measures of variability are available, the                                              variability are available.
IMPROVING status indicator is designated for a statistically                                      – OR – Ten percent or more of the targeted change
                                                                                                  when measures of variability are unavailable.
significant “percent of targeted change achieved,” regardless
of the amount of the change, whereas the LITTLE OR NO              LITTLE OR NO                   Objective demonstrates little or no detectable
DETECTABLE CHANGE status indicator is designated for a             DETECTABLE CHANGE              change, because either:
                                                                                                  – Movement toward the target is not statistically
“percent of targeted change achieved” that is not statistically                                   significant when measures of variability are
significant, regardless of the amount of the change.                                              available.
                                                                                                  – OR – Movement is toward the target but the
    Several steps are required to evaluate statistical                                            objective has achieved less than 10% of the
significance:                                                                                     targeted change when measures of variability are
                                                                                                  unavailable.
     Step 1. The “percent of targeted change achieved” (or                                        – OR – Movement away from the baseline and
“progress quotient,” PQ) is based on the ratio of the simple                                      target is not statistically significant when measures
difference SDt = Rt – Rb between the rate Rt at time t and the                                    of variability are available.
rate Rb at baseline and the targeted change SDT = RT – Rb                                         – OR – Movement is away from the baseline and
between the target rate RT and the rate Rb at baseline:                                           target but the objective has moved less than 10%
                                                                                                  relative to its baseline when measures of variability
                                  SDt                                                             are unavailable.
                          PQ =        × 100.                                                      – OR – No change between baseline and most
                                  SDT                                                             recent data point.

Because the “percent of targeted change achieved” is used          GETTING WORSE                  Movement is away from the baseline and target
                                                                                                  and is either:
only for HP2020 objectives that are moving toward, or                                             – Statistically significant when measures of
meeting or exceeding their targets, PQ ≥ 0.                                                       variability are available.
                                                                                                  – OR – Ten percent or more relative to the baseline
     Step 2. The relative standard error (RSE) of the above                                       when measures of variability are unavailable.
ratio is computed based on the RSE of the numerator and the
denominator. The RSE for the numerator, SDt , is calculated        BASELINE ONLY                  Baseline data only; progress cannot be assessed.
as:                                                                INFORMATIONAL                  Objective is informational (does not have a target).

                                        SE2t + SE2b                DEVELOPMENTAL                  Objective is developmental (does not have baseline
                      RSESDt =                        ,                                           data).
                                        | Rt – Rb |
                                                                   SOURCE: CDC/NCHS, HP2020 database.

Healthy People 2020 Statistical Notes                                                                                                                 5
This approximation assumes the simple difference SDt is             significant, regardless of the value; for an example, see Table
independent of the targeted change SDT .                            3.
    Step 5. An approximate standard error SEPQ for the PQ is             When measures of variability are available, statistical
given by SEPQ = RSEPQ × PQ.                                         significance of the “absolute value of the percent change from
                                                                    baseline” is evaluated using Taylor linearization. A one-sided
      Step 6. Statistical significance of the PQ is assessed
                                                                    0.05-level test is used. Several steps are required to evaluate
using the statistic z = PQ/SEPQ. Because PQ ≥ 0, statistical
                                                                    statistical significance:
significance is based on a one-sided test, which, assuming
normality, compares the value of z to 1.64485 for a 0.05-level          Step 1. The absolute value of the percent change from
test.                                                               baseline (PC) is based on the ratio of the simple difference
                                                                    SDt = Rt – Rb between the rate Rt at time t and the rate Rb at
     When measures of variability are unavailable, the
                                                                    baseline and the rate Rb:
IMPROVING status indicator is designated for objectives that
are moving toward their targets and for which the “percent                   – SDt
of targeted change achieved” is 10% or more. Objectives for                        × 100, when desired direction is increase,
                                                                               Rb         but Rt < RT and Rt < Rb
which the “percent of targeted change achieved” is 100% or           PC =                                                              .
                                                                             + SDt
more have met or exceeded their targets and are designated as                      × 100, when desired direction is decrease,
TARGET MET.                                                                    Rb         but Rt > RT and Rt > Rb

Objectives moving away from their baselines and                     By construction, PC ≥ 0.
targets                                                                  Step 2. The RSE of the PC is computed based on the RSE
                                                                    of the numerator and the denominator in the ratio. The RSE
Direction                                                           for the numerator, SDt , is calculated as:
    ● When the desired direction is increase, an objective is
       moving away from its baseline and target at the most                                           SE2t + SEb2
       recent data point if most recent value < HP2020 target                          RSESDt =
                                                                                                     | Rt – Rb |
       and most recent value < baseline value.
    ● When the desired direction is decrease, an objective is       where SEt is the standard error at time t and SEb is the
       moving away from its baseline and target at the most         standard error at baseline.
       recent data point if most recent value > HP2020 target           Step 3. The RSE for the denominator, Rb, is calculated as:
       and most recent value > baseline value.
                                                                                                       SEb
Extent of movement away from baseline                                                       RSERb =            .
                                                                                                      | Rb |
       Movement away from baseline is quantified using:
                                                                        Step 4. An approximate RSE for the PC is computed
                             Most recent – Baseline
     Absolute value of         value        value                   using first-order Taylor series linearization, assuming the
      percent change =                                  × 100.      simple difference SDt is independent of the baseline rate Rb:
      from baseline              Baseline value
                                                                                                    2
                                                                                     RSEPC =     RSESD t
                                                                                                         + RSER2b .
     A percent change from baseline of 10% or more in
absolute value means that the objective is at least 10% in
                                                                        Step 5. An approximate standard error SEPC for the PC is
deficit relative to its baseline. Such an objective would need to
                                                                    given by SEPC = RSEPC × PC.
make up the deficit from baseline in addition to the desired
targeted change once the baseline value is regained.                     Step 6. Statistical significance of the PC is assessed using
                                                                    the statistic z = PC/SEPC. Because the “absolute value of the
Statistical significance for objectives moving                      percent change from baseline” is used only for objectives that
away from their baselines and targets                               are moving away from their baselines and targets, significance
                                                                    is based on assuming normality and comparing z to 1.64485
     When measures of variability are available, the                for a one-sided 0.05-level test.
GETTING WORSE status indicator is designated for a
statistically significant “absolute value of percent change from        When measures of variability are unavailable, the
baseline,” regardless of the value, whereas the LITTLE OR           GETTING WORSE status indicator is designated for HP2020
NO DETECTABLE CHANGE status indicator is designated                 objectives that are moving away from their baselines and
for a percent change from baseline that is not statistically

6                                                                                                    Healthy People 2020 Statistical Notes
targets and for which the “absolute value of the percent                                                                    Remark. The “percent of targeted change achieved” for
change from baseline” is 10% or more.                                                                                  HP2020 objectives that are moving toward their targets and
                                                                                                                       the “absolute value of percent change from baseline” for those
Objectives for which progress toward target                                                                            moving away from their baselines and targets are calculated
attainment cannot be assessed                                                                                          from the “display” values of the estimates at the baseline
                                                                                                                       and most recent time points—in particular, unless otherwise
     Progress toward target attainment cannot be assessed                                                              specified, rates and percentages are rounded to one decimal
when only baseline data are available, the target was met at                                                           place before being displayed in HP2020 data tables, whereas
baseline, or the objective’s desired direction is to “maintain                                                         standard errors are displayed using three decimal places when
the baseline.” In addition, progress toward target attainment                                                          measures of variability are available. This is consistent with
is not assessed when an objective is informational and does                                                            HP2010, where “display” values also were used in progress
not have a target (e.g., PH-7.3, Increase the proportion of                                                            calculations (3).
population-based HP2020 objectives for which national data
are available by socioeconomic status).
                                                                                                                       Considerations
Illustration of HP2020 classification of objective                                                                          In addition to the aforementioned limitations to using
status                                                                                                                 the “percent of targeted change achieved,” HP2020 progress
                                                                                                                       measures are subject to the following considerations.
     HP2020 contains 42 topic areas with over 1,200
                                                                                                                         ● As in HP2010, the “percent of targeted change achieved”
objectives. A smaller set of HP2020 objectives, called the
Leading Health Indicators, was selected at the launch of                                                                      is calculated using only the target, baseline, and most
HP2020 to communicate high-priority health issues; see                                                                        recent data points. Similarly, the “absolute value of
http://www.healthypeople.gov/2020/Leading-Health-Indicators.                                                                  the percent change from baseline” is calculated using
Table 3 illustrates the HP2020 classification of objective status                                                             only the baseline and most recent data points. As in
using five of these HP2020 Leading Health Indicators.                                                                         HP2010, to facilitate comparisons between objectives,
                                                                                                                              any underlying trends and fluctuations that occur during

Table 3. Objective status classification for selected HP2020 Leading Health Indicators
                                                                                                                                                                                         Movement
                                                                                              Baseline             Most recent                                                           away from              Movement
                                                                                              estimate              estimate                                      Movement              baseline and            statistically
   Objective status                         Objective description                              (year)                (year)                   Target            toward target1            target2               significant3

TARGET MET                   TU-11.1 Children exposed to secondhand                            52.2                   41.3                     47.0                  209.6                     ...                   Yes
                             smoke (percent among nonsmokers aged                          (2005–2008)            (2009–2012)
                             3–11)
IMPROVING                    C-16 Adults receiving colorectal cancer                            52.1                    58.2                   70.5                    33.2                    ...                   Yes
                             screening based on most recent guidelines                         (2008)                  (2013)
                             (age-adjusted percent among adults aged
                             50–75)
LITTLE OR NO                 AHS-1.1 Persons with medical insurance                             83.2                    83.3                    100                      0.6                   ...                    No
DETECTABLE                   (percent among persons under age 65)                              (2008)                  (2013)
CHANGE
LITTLE OR NO                 D-5.1 Persons with diagnosed diabetes                             17.9                   21.0                     16.1                     ...                   17.3                    No
DETECTABLE                   whose A1c value is greater than 9 percent                     (2005–2008)            (2009–2012)
CHANGE                       (age-adjusted percent among adults aged
                             18 and over)
GETTING WORSE                MHMD-1 Suicide (age-adjusted rate per                              11.3                    12.6                   10.2                     ...                   11.5                   Yes
                             100,000 population)                                               (2007)                  (2013)

… Category not applicable.
1Quantified using the “percent of targeted change achieved.”
2Quantified using the “absolute value of the percent change from baseline.”
3When measures of variability are available, statistical significance is based on a one-sided 0.05-level test for either the “percent of targeted change achieved” or the “absolute value of the percent change from baseline.”

DATA SOURCES:
AHS-1.1                      CDC/NCHS, National Health Interview Survey.
C-16                         CDC/NCHS, National Health Interview Survey.
D-5.1                        CDC/NCHS, National Health and Nutrition Examination Survey.
MHMD-1                       CDC/NCHS, National Vital Statistics System-Mortality.
TU-11.1                      CDC/NCHS, National Health and Nutrition Examination Survey.

Healthy People 2020 Statistical Notes                                                                                                                                                                                             7
the intervening years are not considered—because the         important technical and conceptual considerations in the
      number and spacing of data points between the baseline       measurement and tracking of health disparities (3–7). Some
      and most recent data points vary between objectives.         of the considerations that were particularly relevant to the
                                                                   HP2010 health disparities measures and that have provided
    ● As in HP2010, two objectives that are moving toward
                                                                   the impetus for developing the HP2020 health disparities
      their targets may be identical in the “percent of targeted
                                                                   measures are outlined below.
      change achieved” even though they differ in the amount
      of the absolute change from baseline. Similarly, two          ● The percent difference (PD) relative to the best group
      objectives that are moving away from their baselines may         rate was measured only for adverse outcomes in HP2010;
      be identical in the “absolute value of the percent change        see Appendix II. Those dichotomous objectives that had
      from baseline” even though they differ in the amount of          been expressed in terms of favorable outcomes were
      the absolute change from baseline.                               re-expressed using the complementary adverse outcome
                                                                       for the purpose of computing the PD relative to the best
    ● The two measures of progress in HP2020—“percent of
                                                                       group rate.
      targeted change achieved” for objectives moving toward
      their targets and “absolute value of percent change           ● Because the best group rate is theoretically achievable
      from baseline” for objectives moving away from their             by other groups associated with a given population
      baselines—are not comparable because they use different          characteristic, the PD relative to the best group rate can
      measurement standards—targeted change versus baseline            highlight an opportunity for improvement (7). However:
      value. For example:                                              o   In HP2010, concerns about the stability of the best
      o   Objective MHMD-1 is getting worse, having increased              group rate, and, therefore, the reliability of disparities
          by 1.3 percentage points from its baseline—a percent             findings based on the percent differences from the best
          change from baseline of 11.5% in magnitude                       group rate, led to imposing a standard of reliability
          (Table 3).                                                       on its selection. When estimates of variability were
      o
                                                                           available, the RSE of the rate identified as the best
          C-16 is improving, having increased by 6.1 percentage
                                                                           group rate was required to be less than 10%; if it was
          points from its baseline—realizing 33.2% of the
                                                                           not, then the next best rate with RSE < 10% was used
          targeted 18.4 percentage point change from baseline.
                                                                           as the reference for evaluating disparities. As a result,
      o   If, instead, C-16 had achieved just 11.5% of its                 the percent differences that were presented in Healthy
          targeted change from baseline, then it would have                People 2010 Final Review tended to be smaller than if
          increased by only 2.1 percentage points. Thus, even              this reliability standard had not been applied (3).
          though the “percent of targeted change achieved” for         o   The PD expresses disparity for the comparison group
          C-16 would be equal to the “absolute value of the
                                                                           as a percent difference relative to the best group rate.
          percent change from baseline” for MHMD-1, 11.5%,
                                                                           However, to highlight opportunities for improvement,
          the amount of the absolute change from baseline for
                                                                           lack of parity with the best group rate is more readily
          C-16 would be over 1.5 times that for MHMD-1 (2.1
                                                                           expressed using the percent difference relative to
          versus 1.3 percentage points).
                                                                           the comparison group itself. For example, in 2008,
                                                                           approximately 28% of the American Indian or Alaska
                                                                           Native population under age 65 did not have health
Measures of Health Disparities in                                          insurance, compared with 12% of the non-Hispanic
HP2020                                                                     white population under age 65 (best group rate;
                                                                           HP2010 objective 1-1). Thus, relative to the best group
     This section describes the measurement of health                      rate, PD = 133%. However, to express the amount
disparities and changes in disparities over time in HP2020.                by which the uninsurance rate among the American
Detailed information on evaluating the statistical significance            Indian or Alaska Native population under age 65
of the HP2020 health disparities measures when measures of                 would need to be reduced in 2008 to achieve parity
variability are available is provided. The HP2020 disparities              with the best group rate, the percent difference relative
measures are also related to the corresponding HP2010                      to the comparison group would be useful: 57%.
measures, which are described in Appendix II.
                                                                    ● In part for simplicity, but also in part due to the 10%
                                                                       reliability standard imposed on the best group rate, the
Motivation for adopting revised health                                 standard error SEPD for the PD was not used in HP2010
disparities measures in HP2020                                         for assessing the statistical significance of the percent
                                                                       difference, PD. Instead, the simple difference, SD, was
    As is recognized in the Healthy People 2010 Final
                                                                       tested for significance, and the PD was flagged whenever
Review and established elsewhere in the literature, there are
                                                                       the SD was statistically significant at the 0.05 level (1).

8                                                                                                   Healthy People 2020 Statistical Notes
● Measures of health disparities reflect implicit value           standard error of the natural logarithm of the RRg is evaluated
     judgments and trade-offs, particularly in the choice of the    using the formula:
     reference for evaluating disparities, whether to measure
                                                                                                         2             2
     disparities using the absolute or the relative scale, and                                     SEB           SEg
     whether to weight population groups equally or according                       SEln(RRg) =              +             .
                                                                                                   RB            Rg
     to their size. These as well as other conceptual issues
     in the measurement of health disparities are discussed
     elsewhere; see (4,6,7).                                        One-sided significance test for RRg
                                                                     ● Testing RRg = 1 versus RRg > 1 is equivalent to testing
     Because findings of health disparities in HP2010,
especially when using the relative scale, could be affected by                      ln(RRg) = 0 versus ln(RRg) > 0.
whether an objective was expressed in terms of the favorable
health outcome or its adverse complementary outcome (3,4),           ● The statistic for testing ln(RRg) = 0 versus ln(RRg) > 0 is
HP2020 set out to construct measures of health disparities              given by:
that explicitly accounted for an objective’s directionality. In
addition, to account for some of the conceptual issues around                             z = ln(RRg)/SEln(RRg).
absolute versus relative disparities, HP2020 uses a suite of
measures that includes both absolute and relative measures of        ● The rate ratio RRg is statistically significant at the 0.05
overall disparity. The HP2020 approach to measuring health              level if z > 1.64485.
disparities using a suite of measures is consistent with current
practices; for example, it is consistent with the National          One-sided confidence interval for RRg
Cancer Institute’s health disparities calculator (8,9).
                                                                     ● The upper limit (UL) is computed via the inverse
                                                                        transformation as follows:
Comparisons to the best group rate in
HP2020                                                                        UL = exp{ln(RRg) + 1.64485 × SEln(RRg)}.

                                                                     ● A 95% confidence interval for RRg has lower limit =
HP2020 rate ratio (RRg)
                                                                        1.000 and upper limit = UL.
Definition
                                                                    Relation to percent difference from best group
     Let RB denote the best group rate and Rg denote any other      rate
group’s rate. The rate ratio Rg /RB (a common relative measure
in the epidemiologic literature) for comparing Rg to RB can be           The percent difference was used for comparisons to the
modified to yield the following pairwise measure, which will        best group rate in HP2010; see Appendix II.
be referred to as the HP2020 rate ratio and denoted as RRg:
                                                                    Objectives expressed in terms of adverse outcomes
                                        RB       Rg
                       RRg = max             ,        .                  For objectives expressed in terms of adverse outcomes to
                                        Rg       RB                 be reduced, the HP2020 rate ratio RRg is given by
                                                                    RRg = Rg /RB. The HP2010 percent difference PDg relative to
     Note that regardless of whether the objective is expressed     the best group rate is seen as:
as a favorable outcome to be increased—in which case
RRg = RB /Rg—or as an adverse outcome to be decreased—for                                PDg = (RRg – 1) × 100.
which RRg = Rg /RB— the HP2020 rate ratio RRg is
constructed such that RRg ≥ 1.                                          Thus, the HP2010 percent difference PDg is obtained by
                                                                    subtracting 1 from the HP2020 rate ratio RRg and multiplying
Statistical significance                                            by 100 when objectives are expressed in terms of adverse
                                                                    outcomes.
     When measures of variability are available, statistical
significance is based on assuming normality and comparing           Objectives expressed in terms of favorable outcomes
the test statistic to 1.64485 for a one-sided 0.05-level test.
Because the distribution of the rate ratio is typically skewed to        For objectives expressed in terms of favorable outcomes
the right, the natural logarithm transformation is applied first,   to be increased, the rate ratio RRg is given by RRg = RB /Rg.
as described below.                                                 In HP2010, the percent difference PDg was calculated using
                                                                    the complementary adverse outcome, with rates ŘB and Řg.
    When RB and Rg have standard errors SEB and SEg ,               For example, the AHS-1.1 objective shown in Table 4 has
respectively, and are assumed independent, an approximate           the lowest uninsurance rate ŘB = 5.2% (100 – 94.8), realized

Healthy People 2020 Statistical Notes                                                                                                 9
by persons aged 25 to under 65 with an advanced degree,            pairwise absolute differences between population subgroups
whereas the uninsurance rate for those with less than a            will tend to 0.
high school education, say, is Řg = 43.3% (100 – 56.7). The
                                                                      Additionally, the maximal rate ratio is useful for
HP2010 percent difference PDg is given by:
                                                                   comparing objectives that are measured on different scales.
                                Řg – ŘB                                 Even though their simplicity is appealing, the maximal
                       PDg =              × 100.
                                  ŘB                               rate difference and maximal rate ratio are not designed to
                                                                   summarize “typical” or average disparities well, because they
Because the difference Řg – ŘB between the adverse rates is        do not take into account any of the intermediate rates (10).
the same as the difference RB – Rg between the favorable rates,    Instead, the HP2020 summary rate ratio, introduced below,
it follows that the HP2010 percent difference PDg can be           extends the HP2010 index of disparity (4,5) and focuses on a
expressed as:                                                      ratio between the best group rate and the average for all other
                                                                   groups, resulting in a more conservative measure of overall
                           RB           1
                   PDg =        × 1–       × 100.                  health disparity.
                           ŘB          RRg
                                                                   Maximal rate difference (RDmax)
    Thus, the mathematical relationship between the HP2010
percent difference PDg and the HP2020 rate ratio RRg is            Definition
nonlinear when objectives are expressed in terms of favorable
outcomes to be increased.                                              Let RB denote the best group rate and RW denote the worst
                                                                   group rate. The maximal rate difference (RDmax) is an absolute
                                                                   measure of health disparities that compares the highest and
HP2020 measures of overall health                                  lowest group rates in the population for a given characteristic.
disparity                                                          RDmax is calculated as follows:
     In addition to the detailed comparisons to the best group                     RDmax = max{RB – RW, RW – RB}.
rate that the HP2020 rate ratio RRg facilitates, HP2020
provides measures that quantify the degree of disparity overall         Irrespective of whether an objective is expressed in terms
across all groups composing a population domain (e.g., race        of a favorable outcome to be increased—in which case
and ethnicity, education, or income). Unlike in HP2010, where      RRmax = RB – RW—or an adverse outcome to be decreased—
a single relative measure, the summary index, was used (see        from where RRmax = RW – RB—the maximal rate difference
Appendix II), HP2020 uses three measures that include both         RDmax remains nonnegative.
absolute and relative measures of overall disparity:
     ● The maximal rate difference, defined as the simple          Statistical significance
       difference between the highest and lowest rates,                When RB and RW have associated standard errors SEB and
       irrespective of intermediate rates.                         SEW, respectively, the standard error of RDmax is approximated
     ● The maximal rate ratio, defined as the ratio between the    using the following formula, which assumes the two rates are
       highest and lowest rates, irrespective of intermediate      independent:
       rates.                                                                          SERDmax =   SEB2 + SEW2 .
     ● The summary rate ratio, defined using a ratio between the
       best group rate and the average rate for all other groups
                                                                   One-sided significance test for RDmax
       in a population domain—as seen below, for objectives
       expressed in terms of adverse outcomes, the HP2010           ● The statistic for testing RDmax = 0 versus RDmax > 0 is
       summary index is obtained by subtracting 1 from the             given by:
       HP2020 summary rate ratio and multiplying by 100.
                                                                                          z = RDmax /SERDmax
     The maximal rate difference is useful for tracking
changes over time. Tracking the maximal rate difference             ● The maximal rate difference RDmax is statistically
over time allows the analyst to determine whether, overall,            significant at the 0.05 level if z > 1.64485.
the absolute difference between the highest and lowest
rates is decreasing. While this does not capture whether the       One-sided confidence interval for RDmax
population health outcome overall is improving, it does allow
the analyst to evaluate overall progress toward eliminating         ● The UL is computed as follows:
disparities, because as the absolute difference between
                                                                                   UL = RDmax + 1.64485 × SERDmax .
the highest and lowest rates decreases toward 0, all of the

10                                                                                                  Healthy People 2020 Statistical Notes
● A 95% confidence interval for RDmax has lower limit =             HP2020 summary rate ratio (RRave)
     0.000 and upper limit = UL.
                                                                      Definition
Maximal rate ratio (RRmax)                                                 Given that there are K – 1 groups other than the one
                                                                      identified as having the best group rate, compute their average
Definition                                                            rate RA by using the following summation formula:
     Using the same notation as above, the maximal rate ratio                                 R1+ R2 + ... + RK – 1
is defined as:                                                                           RA =                       .
                                                                                                      K_1
                                         RB          RW
                      RRmax = max                ,        .           Continuing with the same notation as previously described,
                                         RW RB                        the HP2020 summary rate ratio is defined as:

     As with the HP2020 rate ratio RRg, note that, regardless                                              RB         RA
of whether the objective is in terms of a favorable outcome to                           RRave = max              ,        .
                                                                                                           RA         RB
be increased or in terms of an adverse outcome to be reduced,
RRmax ≥ 1.
                                                                           As with the HP2020 rate ratio RRg and the maximal rate
                                                                      ratio RRmax, irrespective of the objective’s directionality, the
Statistical significance
                                                                      HP2020 summary rate ratio RRave is such that RRave ≥ 1.
     As with the HP2020 rate ratio RRg , when measures of
variability are available, the natural logarithm transformation       Statistical significance
is applied. Using the same notation as above and, again,
                                                                           In HP2010, the statistical significance of the HP2010
assuming the two rates are independent, an approximate
                                                                      summary index of disparity was assessed using resampling
standard error of the natural logarithm of RRmax is given by:
                                                                      techniques because it was not directly available. In HP2020,
                                                                      when measures of variability are available, the evaluation
                                             2                2       of statistical significance and confidence intervals for the
                                    SEB               SEW
                 SEln(RRmax) =                   +                .   HP2020 summary rate ratio RRave proceeds instead according
                                        RB            RW
                                                                      to the following analytic steps:

One-sided significance test for RRmax                                      Step 1. Assuming the group rates are independent and
                                                                      that K ≥ 3, the standard error SEA of RA is evaluated using
  ● Testing RRmax = 1 versus RRmax > 1 is equivalent to               the following summation formula, which yields an unbiased
     testing                                                          estimate of SEA:
                ln(RRmax) = 0 versus ln(RRmax) > 0.
                                                                                               SE12 + SE22 + … + SEK2 – 1
                                                                                    SEA =                                              ,
  ● The statistic for testing ln(RRmax) = 0 versus ln(RRmax) >                                            K–2
     0 is given by:
                                                                           Step 2. Once RA and SEA are obtained, determining
                      z = ln(RRmax)/SE ln(RRmax) .                    statistical significance of the summary rate ratio RRave
                                                                      proceeds as before. The standard error of the natural logarithm
  ● The maximal rate ratio RRmax is statistically significant at      of RRave is approximately:
     the 0.05 level if z > 1.64485.
                                                                                                              2                2
                                                                                                        SEB            SEA
One-sided confidence interval for RRmax                                              SEln(RRave) =                +                .
                                                                                                         RB            RA
  ● As before, the UL is computed via the inverse
     transformation, as follows:                                      One-sided significance test for RRave
          UL = exp{ln(RRmax) + 1.64485 × SE ln(RRmax)}.                ● Testing RRave = 1 versus RRave > 1 is equivalent to
  ● A 95% confidence interval for RRmax has lower limit =                 testing
     1.000 and upper limit = UL.
                                                                                     ln(RRave) = 0 versus ln(RRave) > 0.

                                                                       ● The statistic for testing ln(RRave) = 0 versus ln(RRave) > 0
                                                                          is computed:
                                                                                            z = ln(RRave)/SE ln(RRave).

Healthy People 2020 Statistical Notes                                                                                                      11
● The summary rate ratio RRave is statistically significant at      summary index IDisp cannot be directly related to the HP2020
        the 0.05 level if z > 1.64485.                                   summary rate ratio RRave when objectives are expressed in
                                                                         terms of favorable outcomes to be increased.
One-sided confidence interval for RRave
     ● The UL is computed via the inverse transformation:                Two examples from the HP2020 health
            UL = exp{ln(RRave) + 1.64485 × SE ln(RRave)}.                disparities tool
     ● A 95% confidence interval for RRave has lower limit =                  The following examples from the HP2020 online health
        1.000 and upper limit = UL.                                      disparities tool, released in spring 2015, serve to illustrate the
                                                                         HP2020 disparities measures; see http://www.healthypeople.gov.
Relation to HP2010 summary index
                                                                         Education disparities in medical insurance for
   The index of disparity (IDisp) was the single summary
measure of health disparities used in HP2010; see                        persons aged 25 to under 65, 2013
Appendix II.                                                                  HP2020 AHS-1.1 objective is to increase the proportion
                                                                         of persons with medical insurance. Accordingly, educational
Objectives expressed in terms of adverse outcomes                        attainment groups in Table 4 are sorted from most to least
                                                                         favorable outcome; here, that is the percentage of persons
     For objectives expressed in terms of adverse outcomes to
                                                                         aged 25 to under 65 in a given group with medical insurance
be reduced, the HP2020 rate ratio RRg for each of the K – 1
                                                                         in 2013.
groups other than the “best” group is given by RRg = Rg /RB .
Similarly, the HP2020 summary rate ratio RRave is given by                    As in HP2010, HP2020 uses the group with the
RRave = RA /RB. Thus,                                                    most favorable (best) rate to highlight opportunities for
                                                                         improvement. Thus, all insurance rates in Table 4 are
                             1
                               ∑ K – 1R
                            K–1 g=1 g
                                              ∑ gK =– 11RRg              compared with the best group rate. For example, the ratio
                  RRave =                 =                              94.8/56.7 between the insurance rate for persons aged 25
                                RB               K–1
                                                                         to under 65 with an advanced degree (best group rate) and
                                                                         the insurance rate for those with less than a high school
    The HP2010 summary index IDisp is obtained by
                                                                         education equals 1.671 (see note, below, about rounding); it
subtracting 1 from the HP2020 summary rate ratio RRave and
                                                                         indicates that the best group rate is 1.671 times the insurance
multiplying by 100 when objectives are expressed in terms of
                                                                         rate among persons aged 25 to under 65 with less than a
adverse outcomes. Indeed:
                                                                         high school education. Said another way, assuming no other
                                                                         changes, the increase in insurance coverage that would be
        ∑ Kg =– 11 PDg ∑ Kg =– 11 (RRg – 1) × 100                        needed among persons aged 25 to under 65 with less than a
IDisp =               =                           = (RRave – 1) × 100.
         K_1                        K_1                                  high school education to achieve parity with those with an
                                                                         advanced degree (best group) is 67.1% [(1.671 – 1.000) × 100].
Objectives expressed in terms of favorable outcomes                           Remark. All disparity calculations in Table 4 are applied
     For objectives expressed in terms of favorable outcomes             to the unrounded values of the estimates and their standard
to be increased, the HP2020 rate ratio RRg for each of the               errors that are available in the HP2020 database. Thus, after
K – 1 groups other than the “best” group is given by                     rounding to three decimals, values displayed in Table 4 for
RRg = RB /Rg. Similarly, the summary rate ratio RRave is                 rate ratios may differ from the results of calculations that use
given by RRave = RB /RA. In HP2010 the percent difference                the displayed values of the estimated rates in Table 4. This
PDg and summary index IDisp were calculated using the                    departs from HP2010, where rounded “display” values were
complementary adverse outcomes, with rates ŘB and Řg. Using              used in disparity calculations (3).
the expression for the percent difference PDg of the adverse                  In particular, working with the unrounded values of the
complementary outcomes derived previously, the HP2010                    estimates and their standard errors (when available) allows
summary index IDisp can be written as:                                   more possibilities for breaking ties in the ranking of rates
                                          K–1
                                                                         from highest to lowest. For example, if, even after comparing
                       RB            1           1                       the rates using their unrounded values, two groups are tied for
             IDisp =        × 1–                        × 100 .
                       ŘB          K – 1 g = 1 RRg                       the highest, most favorable rate, the group with the smaller
                                                                         standard error is selected as the “best” rate when measures
    Note that the average of the reciprocals of the rate ratios          of variability are available. (If measures of variability are
RRg in this last expression is not equal to the reciprocal of the        unavailable, then a tie in the unrounded values of two rates
average or summary rate ratio RRave; thus, the HP2010                    may be resolved using group size or any other characteristic;

12                                                                                                        Healthy People 2020 Statistical Notes
Table 4. Persons with medical insurance (percentage, aged                                                         ● 1.049 times the rate among persons aged 25 to under 65
25 to under 65) by educational attainment: United States,                                                            with a 4-year college degree
2013                                                                                                              ● 1.132 times the rate among those with an Associate’s
                                                                                             Disparity               degree
                                                                                            statistically
  Educational attainment                   Percent                   Disparity              significant           ● 1.185 times the rate among those with some college
                                                                                                                     education
Advanced degree                             94.8                      × 1.000
                                        CI 94.1/95.5                                              ...             ● 1.258 times the rate among those with a high school
                                         SE 0.348                                                                    degree
4-year college degree                       90.3                     × 1.049                     Yes              ● 1.671 times the rate among those with less than a high
                                        CI 89.6/91.0             CI 1.000/1.059
                                                                                                                     school education
                                         SE 0.352
Associate’s degree                          83.7                     × 1.132                     Yes             HP2020 measures of overall disparity
                                        CI 82.6/84.8             CI 1.000/1.146
                                         SE 0.560                                                                     Instead of reporting all pairwise comparisons relative
Some college                                 80                      × 1.185                     Yes             to the best group rate, three measures provided in Table 4
                                        CI 79.0/81.0             CI 1.000/1.200                                  allow for an overall assessment of disparities by educational
                                         SE 0.525                                                                attainment for objective AHS-1.1:
High school                                 75.4                     × 1.258                     Yes              ● Maximal rate difference. The absolute (or range)
                                        CI 74.4/76.3             CI 1.000/1.274
                                                                                                                     difference between the highest and lowest group rates
                                         SE 0.491
                                                                                                                     was 38.1 percentage points in 2013.
Less than high school                       56.7                    × 1.671                      Yes
                                        CI 55.0/58.4            CI 1.000/1.715                                    ● Maximal rate ratio. The highest group rate was 1.671
                                         SE 0.870              Maximal rate ratio                                    times the lowest group rate in 2013.
Average group rate                          77.2                    × 1.227                      Yes              ● HP2020 summary rate ratio. In 2013, the best group rate
excluding best group rate                 SE 0.654              CI 1.000/1.246
                                                                                                                     was 1.227 times the average rate for all other educational
                                                              Summary rate ratio
                                                                                                                     attainment groups (excluding the best), 77.2%.
Maximal rate difference                                               38.1                       Yes
(in percentage points)                         ...                 CI 0.0/39.3
                                                                    SE 0.741                                     Racial and ethnic disparities in infant mortality,
… Category not applicable.
                                                                                                                 2011
NOTES: CI is 95% confidence interval; SE is standard error. Data are for HP2020 objective AHS-1.1:                     HP2020 objective MICH-1.3 is to reduce the rate of all
Increase the proportion of persons with medical insurance. The calculations of the HP2020 rate ratio as
well as the three HP2020 measures of overall disparity, namely the maximal rate difference, the maximal          infant deaths within 1 year of a live birth. Thus, racial and
rate ratio, and the HP2020 summary rate ratio, are as described previously. The statistical significance         ethnic groups in Table 5 are sorted from least to most adverse
of the HP2020 rate ratio and measures of overall disparity is based on one-sided significance tests at the
0.05 level of significance. Similarly, the CIs for the HP2020 rate ratio and measures of overall disparity are   outcome. As before, comparisons are relative to the best group
one-sided 95% CI.                                                                                                rate. For example, the ratio 11.5/4.4 between the infant death
DATA SOURCE: CDC/NCHS, National Health Interview Survey.
                                                                                                                 rate among non-Hispanic black mothers and the infant death
                                                                                                                 rate for Asian or Pacific Islander mothers (best group rate)
the HP2020 summary measures, described above, are not                                                            equals 2.625 (see note, above, about rounding); it indicates
affected by group size).                                                                                         that the former is 2.625 times the best group rate. Thus,
                                                                                                                 assuming no other changes, the infant death rate among non-
     In addition, unlike in HP2010, the identification of the
                                                                                                                 Hispanic black mothers would need to be reduced by 61.9%
best group rate in HP2020 does not require the 10% threshold
                                                                                                                 [100 × (1 – 1/2.625)] to achieve parity with the best group
for its RSE; see “Motivation for adopting revised disparities
                                                                                                                 rate.
measures in HP2020” and (4) for more information.
                                                                                                                      In Table 5, disparities are examined using the rate ratios
    In Table 4, disparities are examined using the rate ratios
                                                                                                                 between each of the other (more adverse) group rates and the
between the best (most favorable) group rate and each of the
                                                                                                                 best (least adverse) group rate.
other (less favorable) group rates.
                                                                                                                 Comparisons to the best group rate
Comparisons to the best group rate
                                                                                                                     In 2011, the best group rate by race and ethnicity for
    In 2013, the best group rate by educational attainment for
                                                                                                                 objective MICH-1.3, 4.4 infant deaths per 1,000 live births,
objective AHS-1.1 was realized by persons aged 25 to under
                                                                                                                 was attained by infants born to Asian or Pacific Islander
65 with an advanced degree. The best group rate was:
                                                                                                                 mothers.

Healthy People 2020 Statistical Notes                                                                                                                                            13
● The rate for those born to non-Hispanic white mothers       Table 5. All infant deaths (per 1,000 live births, under age 1
       was 1.162 times the best group rate.                        year), by race and ethnicity: United States, 2011
     ● The rate for those born to Hispanic or Latina mothers was                                                                                                Disparity
       1.181 times the best group rate.                                                                   Rate per 1,000                                       statistically
                                                                        Race and ethnicity                  live births                  Disparity             significant
     ● The rate for those born to American Indian or Alaska
       Native mothers was 1.882 times the best group rate.         Asian or Pacific Islander                    4.4                       ÷ 1.000
                                                                                                             CI 4.1/4.6                                               ...
     ● The rate for those born to non-Hispanic black mothers                                                 SE 0.131
       was 2.625 times the best group rate.                        White, not Hispanic or                       5.1                     ÷ 1.162                      Yes
                                                                   Latino                                    CI 5.0/5.2             CI 1.000/1.224
HP2020 measures of overall disparity                                                                         SE 0.049

    As before, three measures provided in Table 5 allow for        Hispanic or Latino                           5.2                     ÷ 1.181                      Yes
an overall assessment of disparities by mother’s race and                                                    CI 5.0/5.3             CI 1.000/1.247
                                                                                                             SE 0.075
ethnicity for objective MICH-1.3:
                                                                   American Indian or                           8.2                     ÷ 1.882                      Yes
     ● Maximal rate difference. The absolute (or range)            Alaska Native                             CI 7.4/9.0             CI 1.000/2.075
       difference between the highest and lowest group rates                                                 SE 0.422
       was 7.1 deaths per 1,000 in 2011.                           Black or African                            11.5                    ÷ 2.625                       Yes
     ● Maximal rate ratio. The highest group rate was 2.625        American, not Hispanic                  CI 11.2/11.7            CI 1.000/2.768
                                                                   or Latino                                SE 0.141              Maximal rate ratio
       times the lowest group rate in 2011.
                                                                   Average group rate                           7.5                    ÷ 1.712                       Yes
     ● HP2020 summary rate ratio. In 2011, the average rate for    excluding best group rate                  SE 0.262             CI 1.000/1.847
       all other race and ethnicity groups (excluding the best),                                                                 Summary rate ratio
       7.5 infant deaths per 1,000 live births, was 1.712 times    Maximal rate difference                                                  7.1                      Yes
       the best group rate.                                        (in deaths per 1,000)                           ...                   CI 0.0/7.4
                                                                                                                                         SE 0.192

Changes in health disparities over time in                         … Category not applicable.

HP2020                                                             NOTES: CI is 95% confidence interval; SE is standard error. Data are for HP2020 objective MICH-1.3:
                                                                   Reduce the rate of all infant deaths (within 1 year). Race and ethnicity is that of the mother. The
                                                                   calculations of the HP2020 rate ratio as well as the three HP2020 measures of overall disparity, namely
     In HP2020, changes in disparities over time are assessed      the maximal rate difference, the maximal rate ratio, and the HP2020 summary rate ratio, are as described
                                                                   previously. The statistical significance of the HP2020 rate ratio and measures of overall disparity is based
principally for the three measures of overall disparity            on one-sided significance tests at the 0.05 level of significance. Similarly, the CIs for the HP2020 rate ratio
described above, although changes in disparities for specific      and measures of overall disparity are one-sided 95% CI.

groups relative to the best rate also may be tracked over time     DATA SOURCE: CDC/NCHS, Linked Birth/Infant Death Data Set.

as long as the group with the best rate remains unchanged.
     As stated earlier, tracking the maximal rate difference       highest rate is at least twice the lowest rate, a finding that may
RDmax over time allows the analyst to evaluate overall             motivate action to address disparities among the underlying
progress toward eliminating disparities, because as the            population groups. Highlighting such findings becomes
absolute difference between the highest and lowest rates           useful as the HP2020 initiative assesses progress toward its
decreases toward 0, all of the pairwise absolute differences       overarching goal of eliminating disparities.
between population subgroups will tend to 0. Similarly, as the          When measures of variability are available, the evaluation
maximal rate ratio RRmax decreases toward the value 1.000, all     of the statistical significance of changes in the three HP2020
of the pairwise rate ratios between population subgroups will      measures of overall disparity—as well as changes in the
tend toward the value 1.000.                                       HP2020 rate ratios when the group with the best rate remains
     The HP2020 summary rate ratio extends the HP2010              unchanged—follows from the standard error calculations
index of disparity and focuses on a ratio between the best         detailed previously. The natural logarithm transformation may
group rate and the average for all other population groups for     be used, as appropriate, to correct for lack of normality. The
a demographic or socioeconomic characteristic. The HP2020          difference between the values S1 and S2 of measure S at two
summary rate ratio is more conservative than the maximal rate      time points is tested using a two-sided 0.05-level test based on
ratio. For example, RRave may remain less than 1.100 even          the statistic
if RRmax ≥ 1.100, indicating that, while the highest rate is at
least 10% higher than the lowest rate, intermediate rates may                                                            S2 – S1
be at (near) parity with the best group rate. On the other hand,                                         z=                               .
                                                                                                                          2          2
if the HP2020 summary rate ratio RRave ≥ 2.000, then the                                                             SE1 + SE2

14                                                                                                                         Healthy People 2020 Statistical Notes
You can also read
NEXT SLIDES ... Cancel