Tracking progress toward national health objectives in the elderly: what do restricted activity days signify?

Restricted activity days is the measure by which the 1990 health objectives for prevention of functional disability in older adults will be evaluated. Yet its significance in older populations is poorly understood. We evaluated its use as an outcome measure for a randomized trial designed to impact upon physical function in elderly HMO enrollees. As predicted, restricted activity days was more correlated with physical disability measures than with other health status measures. Distributional properties and rates of missing data were shortcomings.