[Prevalence of anti-hypertensive treatment adherence in patients with resistant hypertension and validation of three indirect methods for assessing treatment adherence].

This study estimated adherence to anti-hypertensive medication using three indirect methods and their combinations in a cohort of patients with resistant hypertension in Rio de Janeiro, Brazil, 2005. The methods used were: self-reported adherence; physicians' adherence evaluation; and the Morisky-Green test (MGT) translated into Portuguese. The predictive validation was performed comparing office blood pressure and ambulatory blood pressure monitoring, measured on two different occasions, from patients classified as adherent or not. The means were compared using non-parametric tests. Two hundred patients were interviewed. Mean age was 63 years (SD = 10.3), and 73.5% were female. Adherence prevalence was 51% using MGT, 52% according to the physician, and 80.5% according to the patient. Adherent patients showed a reduction in both office blood pressure and ambulatory blood pressure, while non-adherent patients did not. The use of more than one method to evaluate adherence showed that non-adherent individuals according to the three methods (11.9%) had the worst evolution in blood pressure levels. This finding suggests that resistant hypertension cannot be attributed exclusively to low adherence.