Intentional prescription nonadherence (noncompliance) by the elderly.

Prescription drugs are not always taken as directed. When there is a discrepancy between the use of a drug and the prescription directions, the drug-taking behavior is considered "nonadherent." To determine the extent of prescription non adherence by old persons and the reasons for nonadherence, an in-home survey was made of 111 elderly subjects who were taking prescription drugs. Drug-taking behavior was compared with the behavior implied by the prescription instructions, the reasons for the differences were sought. Of the study sample, 43 per cent showed such differences in use of one or more prescription drugs. The chief type of discrepancy was underuse (90 per cent of nonadherence). No difference was observed in most of the psychosocial variables studied between those who took drugs as directed and those who did not. Hypertensive subjects did not differ from those without hypertension. A large proportion of nonadherence (73 per cent) was intentional. Intentional nonadherence was more likely to occur in subjects who used two or more pharmacies and two or more physicians. Traditional efforts aimed at reducing the incidence of forgetting to take medicines would not seem to be helpful in cases of intentional nonadherence.