Methods and Limitations
We estimated the percentage of the U.S. diabetic adult population aged 60 years or older who self-reported needing assistance with "activities of daily living" (ADL) and "instrumental activities of daily living" (IADL) using data from the CDC's National Health Interview Survey (NHIS) of the National Center for Health Statistics (NCHS). Conducted continuously since 1957, NHIS is a health survey of the civilian, noninstitutionalized, household population of the United States. The survey provides information on the health of the United States population, including information on the prevalence and incidence of disease, the extent of disability, and the use of health care services. The design of the survey has been described elsewhere.1,2
Adult respondents were asked whether a health professional had ever told them they had diabetes. To exclude gestational diabetes, women were asked whether they had been told they had diabetes other than during pregnancy. To assess ADL, adult respondents were asked “Because of a physical, mental, or emotional problem, do you or anyone in the family need the help of other persons with personal care needs, such as eating, bathing, dressing, or getting around inside this home?” To assess IADL, adult respondents were asked, “Do you or anyone in your family need the help of other persons in handling routine needs, such as everyday household chores, doing necessary business, shopping, or getting around for other purposes?” For our analyses, a positive response to the question indicated functional limitation relative to ADL or IADL. The estimated percentage of the diabetic population needing assistance with ADL or IADL is presented by age groups (60–74, 75+), race/ethnicity (whites, blacks, Hispanics), sex and age groups, and race/ethnicity-age groups. Three-year averages were used to improve the precision of the annual estimates, and 2-year averages were calculated when 3 years of data were not available.
The NHIS may underestimate the true percentage of older adults reporting limitation in performing ADL or IADL for several reasons. First, NHIS is limited to the civilian, noninstitutionalized population and might underrepresent the oldest of the elderly, who are more likely to reside in institutions. Second, this survey excludes persons with severe disabilities who live in institutional settings.3 Finally, the percentages of other race/ethnicity groups with functional limitations were not calculated because of insufficient data.
- Adams PF, Martinez ME, Vickerie JL, Kirzinger WK. Summary health statistics for the U.S. population: National Health Interview Survey, 2010. National Center for Health Statistics. Vital Health Stat. 2011;10(251).
- Botman SL, Moore TF, Moriarity CL, Parsons VL. Design and estimation for the National Health Interview Survey, 1995–2004. Vital and Health Stat. 2000;2(130).
- Guerrero JL, Sniezek JE, Sehagl M. The prevalence of disability from chronic conditions due to injury among adults ages 18-69 years old: United States, 1994. Disabil Rehabil 1999;21(4):187-192.