Medical conditions differentially affect the development of IADL disability: implications for medical care and research.

Using The Longitudinal Study of Aging, we determined the independent effects of nine self-reported medical conditions on the likelihood of developing specific instrumental activities of daily living (IADLs) disabilities at three points in time. We controlled for demographic factors and self-reported health status. The various medical conditions differentially affect each specific IADL disability, and each IADL disability has its own set of predictors which, in general, do not vary over time. The differential effects of thse predictors need to be taken into consideration by researchers, clinicians, and policymakers when studying disability and when implementing and evaluating programs to reduce disability.