Measurement issues in health-related quality of life assessments in physical activity research /

Abstract

In physical activity research, health-related quality of life (HRQOL) is an outcome variable of growing importance. Physical activity is directly associated with HRQOL and intervention-type studies seek to show improvements in HRQOL based on treatment effects. As interest grows in using HRQOL as an outcome measure in physical activity research, the need to investigate the measurement properties of HRQOL assessments increases in importance. The first objective of this project was to explore HRQOL assessments used in physical activity research by examining their instrument characteristics (items, dimensions, scoring, etc.) and their published psychometric properties. The second objective of this project was to investigate the reliability of the most commonly used HRQOL assessment in physical activity research, the Short Form Health Survey (SF-36). The specific aim of the second study was to investigate the extent to which the reliability of the SF-36 generalizes across various types of physical activity studies. The third and final objective of this project was to evaluate the SF-36 for proper measurement functioning using the Rasch model. Results of these studies showed that 10 HRQOL assessments are currently used in physical activity research and recommendations were made relative to different study designs. It was also found, through meta-analytical procedures, that the SF-36 provides strong reliability evidence across a wide range of physical activity research. Finally, the SF-36 met stringent modern measurement criteria using the Rasch model.