Comparative cohort trends of black-white disparity among obese and non-obese older adults

Late-life disabilities such as ADL and IADL limitations are associated with elevated mortality and health risks. These risks are exacerbated for obese individuals as they tend to have higher rate of disability than non-obese individuals. As newer cohorts of older adults may experience longer duration of obesity than earlier cohorts due to improved medical technology, we expect that recent obese cohorts would show higher rate of disability than earlier cohorts. Further, although we have examined the age-period-cohort trends of black-white disparities in ADL and IADL disabilities, the disparity trends by obesity status have not yet been explored. Using the National Health and Nutrition Examination Survey (NHANES) and age-period-cohort models, our preliminary results showed that ADL and IADL disabilities for individuals aged 70 and older declined across earlier cohorts; however, the trends showed a small uptick from the 1925 cohort for ADL disability and from the 1935 cohort for IADL disability. The trends of black-white disparity for ADL and IADL disabilities were quite flat across the cohorts for obese individuals; whereas, ADL and IADL disparities generally declined for non-obese individuals. We also found that obese individuals tend to have lower ADL and IADL disparities than non-obese individuals which suggests that obesity might have attenuated the black-white disparities in disability. Finally, we compared our NHANES results to NHIS dataset using the same statistical model for robustness check and found similar black-white disparity trends except that obese individuals tend to show slightly declining ADL and IADL disparities in the NHIS dataset.