Factors predicting change in prescription and nonprescription drug use in a community-residing black and white elderly population.

The current study identifies characteristics that predict change in use of prescription and nonprescription drugs over a period of 3 years. A modified health care services use model was applied to information obtained from a probability-based sample of black (n = 1778) and white (n = 1446) community-resident elderly, interviewed in 1986-1987 and 1989-1990. Analysis was by means of logistic and ordinary least-squares regression, with sample weights and design effects taken into account. The number of users and average number of prescription drugs used increased over the 3 years, and was best predicted by extent of prior drug use, older age, white race, poorer health, and number of health care visits. Conversely, nonprescription drug use declined significantly, and was best predicted by prior use, white race, and female gender. The reduced use of prescription drugs by blacks as compared to whites is of concern, suggesting that attention is needed to assure equitable access to prescription drugs.