Compliance and compliance-improving strategies in hypertension: the Japanese experience.

The clinical records of 1187 patients starting antihypertensive treatment during the period 1969-1979 were reviewed at the end of 1983. The annual drop-out rate was 21.0% in the first year, decreased in subsequent years and was about 1% after five years. The medication compliance of 381 patients was estimated by interview in 1980. Of all 381 patients, 243 (63.8%) reported taking 95-100% of prescribed drugs. Medication compliance was related to the frequency and timing of dosing rather than to the number of drugs. Once daily regimens had better compliance than three times daily ones, and medication compliance was greatest for morning dosing, second greatest for evening dosing, and least for dosing at noon. Repeated assessment of medication compliance on three successive years was followed by gradual improvement of compliance without any other intervention.