A longitudinal evaluation of drug use in an ambulatory elderly population.

Participants in a geriatric health screening program were studied longitudinally to determine the patterns of drug use over a 10 year period. There were 314 (34.0%) men and 610 (66.0%) women who completed 10 yearly health screening evaluations. The mean number of prescribed and non-prescribed drugs used per participant increased from 2.90 in 1978-79 to 4.08 in 1987-88 (p less than 0.0001). There was no significant difference between men and women in the rate of increased drug use. There was no significant increase in the mean number of drug ingredients per participant used over the 10 year period. The most frequently reported therapeutic categories for 1978-79 were antihypertensives, analgesic-antipyretics, antirheumatics, multiple vitamins, cathartics and vitamin E, which represented 10.2, 7.2, 6.5, 4.9, 4.8 and 3.8% of all categories used. There was a decline in all of these categories between interval 1 and 10. Increased use of drugs, particularly prescribed medications, by the elderly population may present problems of adverse drug reactions, drug interactions and medication compliance in the future. Changing patterns of drug use may have resulted, in part, from introduction of new therapeutic classes and from new treatment concepts over the 10 year study period.