Racial disparities in poststroke activity limitations are not due to differences in prestroke activity limitation

Background African Americans experience greater poststroke disability than whites. We explored whether these differences are because of differences in prestroke function. Methods The Panel Study of Income Dynamics (PSID) is a nationally representative US panel survey of families and their descendants. We included all PSID respondents who reported an incident stroke between 2001 and 2011. Our primary outcome was an index representing the sum of total activities of daily living (ADL) limitations (0-7), and the secondary outcome was an index of instrumental activities of daily living (IADL) limitations (0-6). Survey-weighted descriptive statistics and Poisson regression were used to estimate racial differences in ADL and IADL before, with, and after the wave when incident stroke was reported. Results A total of 534 incident strokes were identified, 198 (37%) in African Americans. There were no prestroke racial differences in activity limitations (.7 versus.7, P =.99). In the wave of the incident stroke (between 0 and 2 years from incident stroke), African Americans had considerably more ADL limitations than whites (2.2 versus 1.5, P =.048). These racial differences persisted after adjusting for age, sex, and comorbidities. For IADLs, adjusted models suggested small prestroke racial differences and larger poststroke differences. Conclusions Racial disparities in poststroke ADL limitations are not due to prestroke activity limitations. Instead, differences appear largest in the first 2 years after stroke.