Quality-of-life measures in the evaluation of antihypertensive drug therapy: Reliability, validity, and quality-of-life domains

Health care policy decision makers and clinicians have come to realize that drug therapy should offer more than just efficacy and safety, which are determined in controlled clinical trials. During the last decade, quality of Life (QOL) has become one of the most important variables in selecting which drug therapy should be used in a particular patient population. This is especially the case with antihypertensive drug therapy in which clinicians and patients have to make trade-offs between the increased health risk of hypertension and the common side effects of antihypertensive therapy. Maintenance therapy is the key to successful control of high blood pressure, however, the side effects of drug therapy may lead to a decrease in patient compliance, a decrease in treatment success, and a reduction in a patient's QOL. In the assessment of QOL, the use of reliable and valid instruments to measure the appropriate domains is crucial. We reviewed 76 clinical trials involving antihypertensive drugs in which the QOL of patients as one of the outcome measures was evaluated. The problem of inadequate information on the psychometric properties of the instruments used to measure QOL was found to be most serious when the instruments were created specifically for individual studies. Of the clinical trials involving: the use: of these self-created instruments, only 4% provided any kind of reliability, and only 13% provided any kind of validity information. The most commonly measured QOL domains in these clinical trials were symptomatic well-being/side-effect profile, psychological well-being, sleep, sexual function, and positive well-being and social participation. The reliability and validity data were generally available for the instruments measuring psychological well-being. More work is needed to establish the validity of the instruments measuring positive well-being and social participation, sleep, and sexual function. Clinical studies on the QOL of patients receiving antihypertensive therapy should use instruments with established reliability and validity data, which measure the QOL domains relevant to the patient and to the intervention being evaluated.