Disability and Health Data System (DHDS) Methods
Disability and Health Data System (DHDS) contains data on disability status and types, demographics, and health topics for the United States, the District of Columbia, and select U.S. territories. The methodology for calculating these estimates is specific to DHDS and might not be applicable outside of this system. Therefore, estimates in DHDS may not match those reported in other Centers for Disease Control and Prevention (CDC) data systems and reports.
To see a list of indicators and how they were defined, please see the Data Guide. The data guide provides detailed information for each indicator, including: definition, specific analysis criteria, years for which the data are available, and a citation if the definition was based on a publication.
Data are from the Behavioral Risk Factor Surveillance System (BRFSS), a state-based, telephone health survey of civilian, non-institutionalized adults 18 years of age and older. All 50 states, the District of Columbia, Puerto Rico, Guam, and the U.S. Virgin Islands conduct the survey. With assistance from the Centers for Disease Control and Prevention (CDC), trained interviewers collect comprehensive demographic, health condition, health risk behavior, and preventive health data. Get detailed information about BRFSS, including BRFSS questionnaires, codebooks, and methodology information.
Analyses were performed using SAS (SAS Institute, Inc., Cary, North Carolina) and SAS-callable SUDAAN (Research Triangle Institute, Research Triangle Park, North Carolina) to account for the BRFSS complex survey design. Prevalence estimates were calculated, as well as corresponding 95% confidence intervals (95% CI) and weighted numbers. All estimates were weighted to account for the probability of selection, nonresponse, noncoverage of households without a telephone, the number of adults in a household, the number of telephones in a household, and to adjust to population totals for each state or territory. Most estimates were age-adjusted to the 2000 U.S. standard population, with the exception of estimates stratified by age.1 For each indicator, “Don’t know” and “Not sure” responses were set to missing. Respondents with missing data for an indicator were not included in analyses involving that indicator. Estimates were suppressed if the standard error was greater than or equal to 30% of the estimate, if the unweighted total population was less than 50, or the standard error equaled 0.
Data are available for all 50 states, the District of Columbia, Puerto Rico, Guam, and the U.S. Virgin Islands, individually. Data were also aggregated to produce estimates for the ten U.S. Department of Health and Human Services regions,2 and the U.S. and Territories combined.
The prevalence of disability status and select disability types (cognitive, hearing, mobility, vision, self-care, and independent living) were calculated among adults overall, and by the following demographic characteristics: age, sex, race/ethnicity, and veteran status.
Demographic (income level, education level, marital status, and employment status) indicators in DHDS were analyzed by disability status and types to present prevalence estimates among adults with and without any disability and by six select disability types (cognitive, hearing, mobility, vision, self-care, and independent living).
Health topic indicators are displayed in DHDS in the following categories: Health Risks & Behaviors, Prevention & Screenings, Barriers & Costs of Health Care, General Health Conditions, Chronic Conditions, and Mental & Emotional Health.
Health topic indicators were analyzed by disability status and types to present prevalence estimates among adults with and without any disability and by four select disability types (cognitive, hearing, mobility, and vision).
Health topic indicators were also analyzed by disability status and three demographic groups. These analyses present prevalence estimates among adults with and without any disability, and additionally by age groups (18-44, 45-64, and 65+ years)1, sex (male, female), or race/ethnicity (white, black, Hispanic, other/multirace).3
The estimates presented in DHDS are subject to a number of limitations. First, BRFSS is a telephone survey and may have higher levels of non-coverage than an in-person interview, as some households are unable to be reached by telephone. Second, BRFSS data are self-reported and subject to recall bias, and may be less accurate than data based on physical measurements (e.g., height, weight, and blood pressure). Third, BRFSS does not include people living in institutions or group homes. Since people residing in such facilities may be more likely to have a disability, the prevalence of disability may be underestimated. Fourth, the questions in BRFSS used to define disability do not include information on permanence, duration or underlying medical condition.
- Although most indicators were age-adjusted or stratified using three age groups—18-44, 45-64, and 65+ years—these age groups do not apply to all indicators.
- U.S. Department of Health and Human Services. Regional Offices. [Updated 2014 April 15; Cited 2017 June 20]. Available from: https://www.hhs.gov/about/agencies/iea/regional-offices/external icon.
- All respondents identified as white, black, and other (includes Asian, Native Hawaiian or Other Pacific Islander, and American Indian or Alaska Native) were non-Hispanic. Respondents identified as Hispanic might be of any race.