Effect of Active Telephone Calls in the Compliance of Hypertensive Patients With Treatment: An Open and Randomized Clinical Trial

To evaluate the importance of providing guidelines to patients via active telephone calls for blood pressure management and the discontinuation of treatment in hypertensive patients, using two treatment regimens with low-dose medications, which were offered for free to avoid the influence of the financial factor. We opted for a regimen called "traditional" based on diuretics and beta-blockers, and another one called "current" treatment based on the angiotensin II antagonist and calcium channel blocker.

Patients and Methods The patients studied were those with essential hypertension who could receive telephone calls to be reminded of the dates of their medical appointments and to receive guidance about hypertension; patients were of both genders, from any ethnic background, over 18 years old and with body mass index below 40 kg/m2, and were enrolled in the study after signing a free and informed consent term. The study was approved by the Ethics Committee of the Board of Directors in the General Hospital at the São Paulo University School of Medicine.

Exclusion criteria were patients with blood pressure < 140/90 mm Hg without antihypertensive medication, pregnant women or nursing mothers, patients with secondary hypertension, white-coat hypertension with systolic pressure ≥ 140 mm Hg and/or diastolic pressure ≥ 90 mm Hg at the doctor's office and awake mean systolic pressure < 135 mm Hg or awake mean diastolic pressure < 85 mm Hg without antihypertensive medication, malignant hypertension, presence of liver dysfunction evidenced by the patient's clinical history or by one of the liver function tests with levels twice the normal values (alkaline phosphatase, total bilirubin, aspartate aminotransferase), patients with clinical conditions that might interfere with the total conformity with the study or those who might have increased risk for participating in the study, patients with previous history of hypersensitivity reaction to the study medications, patients with a history of alcoholism, drug abuse or mental disorders that might invalidate the free and informed consent or limit the patient's ability to meet the protocol rules, patients who had participated in any other studies involving investigational drugs or drugs already marketed within the previous month, before enrollment in this study or concomitantly with this study.

Measurement of blood pressure was performed five times by the nursing staff in right upper limb, with patient sitting, using a cuff of appropriate size to the arm and a validated automatic oscillometric device (Dixtal, DX 2710, São Paulo, Brazil) The mean of the last two measurements was calculated and recorded as long as the difference between these measurements was less than 4 mm Hg. If after the 5 measurements the difference between the last two ones was higher than 4 mm Hg, the measurement was repeated until the difference between the two measurements was less than 4 mm Hg.

The diagnosis of hypertension was made when the mean values of the last two measurements were: systolic pressure ≥ 140 mm Hg and/or diastolic pressure ≥ 90 mm Hg with or without medication in the initial visit (Visit 0). Patients who were receiving antihypertensive medication at the initial visit and had systolic pressure < 140 mm Hg or diastolic pressure < 90 mm Hg were re-evaluated 8 weeks after discontinuation of their medication and introduction of placebo, and they were included in the study when the mean values were systolic pressure ≥ 140 mm Hg and/or diastolic pressure ≥ 90 mm Hg.