Objective: To validate six indirect methods, which were simple and easy to apply in clinical practice, of identifying patients who did not comply with drugs treatment for hypertension.
Design: A prospective study based on two visits to patient's home.
Setting: rural health centre at Calpe, Alicante.
Patients: 174 patients (58 men and 116 women) were included. They were chosen at random from the centre's records of hypertense patients.
Measurements and main results: Compliance was assessed by the method of a surprise counting of pills in the patient's home. Patients who had between 80 and 110% compliance were defined as compliant. The six indirect methods validated were: communication of self-compliance (CS), attendance at appointments (AA), doctor's judgment (DJ), information about the illness (II), hypertension control (HC) and the Morisky-Green test (MG). II was the most sensitive (81.9%). CS reached the highest specificity (93.4%), the best positive predictive value (81.8%) and the best concordance index (kappa, 0.26).
Conclusions: II and CS are the indirect methods with the best validity indicators and could be used together to assess compliance with drugs treatment for hypertension.