Assessing health-related quality of life in HIV disease: key measurement issues.

The reliable and valid assessment of health-related quality of life (HRQoL) in human immunodeficiency virus (HIV) clinical research presents both familiar and unique challenges. Consistent with HRQoL research in general, measures of HRQoL in HIV disease must meet a set of standard psychometric properties, produce interpretable results, and be responsive to relatively small treatment effects. Furthermore, as clinical research for a range of diseases and conditions becomes increasingly global, HRQoL investigators are confronted with the formidable task of developing measures that are applicable across a range of cultures and languages within and across national boundaries. In this paper, we present a model of HRQoL to be applied across disease and conditions, with a discussion of the key measurement issues. We then briefly consider the natural history and treatment aspects of HIV that are relevant to HRQoL research. In the final sections of the paper, we describe the elements needed in an 'ideal' HRQoL/HIV instrument and propose a method for evaluating the degree to which current HRQoL measures address the challenges posed by HIV clinical research.