BENEFITS OF ELECTRONIC PILLBOXES IN EVALUATING TREATMENT COMPLIANCE OF PATIENTS WITH MILD-TO-MODERATE HYPERTENSION

Objective This study was designed to assess the compliance of hyperten sive patients with a once-daily regimen of the angiotensin converting enzyme (ACE) inhibitor trandolapril and to evaluate the antihypertensi ve efficacy of the drug in relation to the time interval between takin g the final dose and measuring the blood pressure (BP). Design After a 2-week wash-out period, hypertensive patients, recruited by cardiolog ists, received trandolapril 2 mg once daily in the morning for 4 weeks . Methods In order to assess compliance, each patient's supply of tran dolapril capsules was presented in a pillbox that incorporated in its lid a microprocessor that recorded the date and time of each occasion that it was opened. BP was measured using validated semi-automatic dev ices, at the end of both the wash-out and the treatment period. Result s A total of 590 patients entered the study. Compliance data were eval uable for 501 patients. Overall compliance, defined as the ratio of th e number of openings recorded to the number of doses prescribed was le ss than 80, 80-100, and more than 100% in 17, 63 and 20% of patients, respectively. The average number (+/- SD) of missed doses was 4.5 +/- 8 (median 2). The average interval between successive openings was 25 h 07 min mean +/- 13 h (median 24 h). The average number of delayed do ses (a delayed dose being defined as the box being opened 25-36 h afte r the previous occasion) was 5.6 +/- 3 (median 6), Patients living in the Paris area had more forgotten and delayed doses than those living in the provinces (7.9 versus 3.8 forgotten; P<0.0001 and 6.3 versus 5. 5 delayed; P<0.005), Doses were forgotten and delayed more often durin g weekends than on weekdays. The greatest number of delayed doses occu rred in those patients under 60 years of age (6.0 versus 5.2; P<0.01), Decreases in systolic blood pressure (SEP and diastolic blood pressur e (DBP) were 20.3/12.8 mmHg, for patients whose final drug was taken o n the same day as the BP measurement, and 18.9/11.2 mmHg for patients whose final dose was taken on the previous day. Conclusions Electronic compliance monitoring allows refined analysis of the behaviour of hyp ertensive patients. In this study doses were missed and delayed freque ntly during the first month of treatment, depending on the patient's l ifestyle.