Consequences of intermittent treatment for hypertension: the case for medication compliance and persistence.

OBJECTIVE: To review patient compliance with once-daily antihypertensive medications and the impact of partial compliance on healthcare outcomes. DATA SOURCES: A MEDLINE search of the literature using the terms "patient compliance," "antihypertensive medications," and "hypertension" for the period 1976-1996 was conducted. In addition, papers cited in reference lists of source articles were reviewed. STUDY SELECTION: Articles were selected if they described patterns of compliance, including rates for differing dosing regimens. Articles discussing once-daily dosing were selected only if they included information on the methodology for compliance assessment. Thirteen reports met these criteria. DATA SYNTHESIS: Patterns of compliance vary, with only a partial relationship to dosing regimens. Overall compliance was 76% for once-daily antihypertensive medications, with a wide range found (53% to 85%). These data were comparable to the mean 75% compliance found for other medical disorders.
CONCLUSIONS: Persistence with treatment is necessary for reduction of long-term consequences of hypertension. Enhancing compliance with antihypertensive medications could thus have a profound impact on health outcomes. Once-daily dosing should be coupled with selection of a drug with long duration of action to overcome problems of missed doses. Widespread adoption of simple compliance enhancement methods could lead to decreased morbidity and mortality from cardiovascular disease and stroke.