Physical activity and health-related quality of life in chronic low back pain patients: a cross-sectional study

Background: The aim of the present study was to identify the relationship of physical activity (PA) and Health-Related Quality of Life (HRQoL) in patients suffering from low back pain (LBP). Methods: The present evaluation was conducted as a cross-sectional study based on baseline data of an randomized controlled trial on the effectiveness of an intervention promoting PA. Patients answered a questionnaire on domain specific PA (GPAQ) and HRQoL (EQ-5D-5 L). Furthermore, sociodemographic and indication-specific variables as well as work-related aspects were assessed. Associations of PA and HRQoL were estimated by means of regression analysis: one regression model only included domain specific PA (model 1) and a second regression model additionally included further variables (model 2). Results: 412 patients completed the questionnaire. Model 1 showed opposed effects of workplace and leisure time PA: while workplace PA showed a negative association (beta = -0.064; p = 0.04), a positive association of leisure time PA could be proved (beta = 0.068; p = 0.01). Model 2 showed that only the variables "current work ability" (beta = -0.030; p < 0.01) and "intensity of pain" (beta = 0.104; p < 0.01) significantly contributed to explain the variance in HRQoL (model 2). Conclusions: The present results indicate the necessity of a differentiation of workplace and leisure time PA in the context of assessing health-enhancing effects of PA in LBP patients. In the context of HRQoL it must be assumed that the relevance of PA might be overestimated. Further research should be performed on predictors of HRQoL and thereby particular attention should be paid on the patients' work-related and indication-specific aspects.