Who participates? Accounting for longitudinal retention in the MIDUS national study of health and well-being.

OBJECTIVE This article uses data from MIDUS (Midlife in the United States), a national study of Americans (N = 7,108), to investigate factors that predict longitudinal retention. With its extensive age range (25-75 at Time 1) and long-term design (9- to 10-year survey interval), MIDUS is useful for investigating common sociodemographic and health predictors of continuing participation. METHOD The authors conducted logistic regression analyses of baseline sociodemographic and health variables predicting retention. Select interaction terms examined the interplay between targeted variables. RESULTS Consistent with prior research, higher retention rates were found among Whites, females, and married individuals as well as those with better health and more education. Interaction analyses further clarified that (a) health status better predicted retention among older compared to younger respondents and among women compared to men, (b) marital status better predicted retention among Whites compared to non-Whites and among women compared to men, and (c) economic status better predicted retention among those with poorer functional health status. DISCUSSION The authors' analyses clarify that longitudinal retention varied depending on respondents' sociodemographic characteristics and their health status. The unique contribution of this article is that factors predicting nonparticipation can be offset by, or compensated for, other factors.