Relation between insufficient response to antihypertensive treatment and poor compliance with treatment: a prospective case-control study.

Abstract

To prospectively compare compliance with treatment in patients with hypertension responsive to treatment versus patients with treatment resistant hypertension. Prospective case-control study. Outpatient department in a large city hospital in Switzerland, providing primary, secondary, and tertiary care. 110 consecutive medical outpatients with hypertension and taking stable treatment with at least two antihypertensive drugs for at least four weeks. Treatment compliance assessed with MEMS devices; blood pressure determined by 12 hour daytime ambulatory monitoring (pressure <135/85 mm Hg in patients aged </=60 years and <155/90 mm Hg in patients aged >60 indicated hypertension responsive to treatment). Complete data were available for 103 patients, of whom 86 took >/=80% of their prescribed doses ("compliant") and 17 took <80% ("non-compliant"). Of the 49 patients with treatment resistant hypertension, 40 (82%) were compliant, while 46 (85%) of the 54 patients responsive to treatment were compliant. Non-compliance with treatment was not more prevalent in patients with treatment resistant hypertension than in treatment responsive patients.