 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 kgm2, 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. 