Inappropriate medication use and health outcomes in the elderly.

Inappropriate medication use is a major problem for the elderly. Although increasing attention has been paid to inappropriate prescription medication use, most previous research has been limited to the investigation of prevalence and trends. Few studies provide the empirical evidence for the adverse effect of inappropriate medication use on health outcomes at the national level. This study is the first attempt to assess the relationship between inappropriate prescription use and health status for the elderly in the United States. Based on the 1996 Medical Expenditure Panel Survey, inappropriate medication use in a national representative elderly population was first identified using Beers criteria. A survey type of ordered probit model was then estimated to quantify the effect of inappropriate drug use on patient self-perceived health status measured using a five-point scale (poor, fair, good, very good, and excellent). After controlling for a set of possible confounding factors, it was found that individuals using inappropriate medications in Round 1 were more likely than those not using inappropriate medications to report poorer health status in Round 2. Other risk factors for poor health status include a higher number of prescriptions, being black, having low education, and having one or more chronic diseases. This study provides strong evidence of a significant adverse effect of inappropriate medication use on patient health status. These findings lend partial support to the use of Beers criteria in assessing the quality of prescribing and the appropriateness of medication use in the elderly population.