Self-reported measures of health-related quality of life (HRQOL) are increasingly used in clinical management and evaluation of patient outcomes. HRQOL measures are used to monitor patient progress and treatment response, investigate effects of medical interventions, and provide patient-based data for quality improvement initiatives and policy decisions. Given the importance of HRQOL, it is imperative that the instruments used to assess HRQOL are precise, valid, reliable, and responsive, and that the HRQOL data are appropriately collected, analyzed, and presented. This article reviews the key attributes of studies involving HRQOL data, discusses best practices for selecting appropriate instruments, and provides guidelines for the assessment, analysis, and presentation of these data. A checklist and a reviewer guide are included to serve as templates for authors and reviewers when submitting and reviewing studies involving HRQOL. [ABSTRACT FROM AUTHOR]