Evaluating the predictive validity of nursing home pre-admission screens.

This article demonstrates a method for evaluating the predictive validity of nursing home pre-admission screens (PAS) by using measures of predictive validity adapted from the field of epidemiology. Our approach estimates how well as PAS performs in identifying the "who but for" population of the Medicaid home and community-based services waiver programs for the frail elderly. The methodology's usefulness in screen revision is also illustrated.