Quality of life in hypertensive patients on different antihypertensive treatments: rationale for methods employed in a multicenter randomized controlled trial

Abstract

In measuring the quality of life and other such end points in a trial, it is widely recognized that poor methods and observer and subject bias may invalidate the results. The measurement of two aspects of the quality of life, activity and well-being, is attempted using methods which include valid, repeatable assessments that are also sensitive to the actions of pharmaceutical agents. Methods are described for use in a randomized controlled trial to measure three aspects of well-being: symptoms, activity, and psychological status. These methods are employed in a single-blind randomized trial of a combination of oxprenolol plus diuretic compared with captopril plus diuretic in 97 patients with mild to moderate hypertension. The patients are from West German centers involved in a multicenter European study. In 34 (35%) of the patients, well-being was assessed from a self-administered questionnaire, and in the remaining 63 patients the investigators interviewed the patients and asked the same questions. Data are presented at entry to the trial. The methods appeared to be successful at that stage and the results were comparable with those for similar studies in London. Activity, well-being, and psychological status were sufficiently correlated to suggest that the methods are valid estimates of certain aspects of the quality of life. However, two major problems remain. Less disability was reported when the questionnaires were completed by the investigators; and after randomization their nonblindness must raise doubts about the objectivity of interviewer-derived data. The results of the trial may have to be assessed solely from self-administered questionnaires.