Generic Health-Related Quality of Life May Not Be Associated with Weight Loss 4 Years After Bariatric Surgery: a Cross-Sectional Study

Background There seems to exist a belief that weight loss is proportionally associated with improvement of health-related quality of life (HRQoL) after bariatric surgery. HRQoL is a complex multidimensional construct of one's perception of health and well-being and is measured through generic and disease specific questionnaires. Objectives This study aimed to test the associations between weight loss after bariatric surgery and both generic and obesity-specific HRQoL, and mental distress, controlling for other patient characteristics. Methods The study was conducted at the Department of Surgery at Haugesund Hospital (Norway) based on a cohort of bariatric surgery patients operated between 2010 and 2013. Primary outcome measures included the SF-36 (generic HRQoL), IWQoL-Lite (obesity-specific HRQoL), and HADS (mental distress). Blocks of variables (time since surgery, personal characteristics, socioeconomics, comorbidities, surgical complications, experienced life crisis, and weight loss) were entered into hierarchical linear regression models with the four outcome measures as dependent variables. Cumulative explained variance (r(2)) and increase in r(2) after the entry of each block of variables is reported. Results A total of 206 completed the outcome measures with a mean (SD) of 4.4 (1.1) years after surgery. The generic SF-36 physical and mental composite scores were significantly associated (p < .05) with socioeconomics, baseline comorbidities, and surgical complications. Obesity-specific IWQoL-Lite scores were significantly (p < .05) associated with weight loss. Conclusions The study indicates that post-operative weight loss is associated with obesity-specific HRQoL but demonstrates no associations between weight loss and generic HRQoL, when controlling for other patient characteristics.