COMPARISON OF HEALTH-RELATED QUALITY-OF-LIFE IN CLINICAL-TRIAL AND NONCLINICAL TRIAL HUMAN IMMUNODEFICIENCY VIRUS-INFECTED COHORTS

Clinical trials randomly assign treatments and select participants to maximize internal validity, but such selection threatens generalizabil ity by excluding important groups with the diseases under study. Parti cularly in human immunodeficiency virus (HIV) disease, the results of clinical trials are applied broadly to populations, despite limited re presentation by minorities and disadvantaged groups. Health-related qu ality of life (HRQOL), which is increasingly recognized as an importan t outcome in these studies, may be sensitive to differences that affec t generalization of trial results to target populations. This study co mpared HRQOL in two HIV-infected cohorts: 1) multicenter AIDS Clinical Group Trials in which most subjects are white, privately insured, and high-income (n = 1,907); and 2) a study of ethnically diverse, low-in come patients recruited from public clinics (n = 205). Both studies in cluded 30 HRQOL items developed in the Medical Outcomes Study (MOS) an d items on symptoms, medications, and demographic characteristics. HRQ OL scores were significantly lower in the nontrial sample (P < 0.001) by about one standard deviation, even after direct adjustment for clin ical and demographic characteristics, and also after comparison of the nontrial sample with the most symptomatic in the trial sample. The re lationships of characteristics with HRQOL differed between nontrial an d trial samples, suggesting problems generalizing results from HIV cli nical trials to important target populations. HRQOL measures such as t hose from the MOS can be useful in detecting differences that affect g eneralization.