Abstract
BACKGROUND: Evidence on the long-term (≥10 years) development of health-related quality of life (HRQoL) following bariatric surgery is still limited and mainly based on small-scale studies. This study aimed to investigate (1) 15-year changes in mental, physical, social, and obesity-related HRQoL after bariatric surgery and non-surgical obesity treatment; and (2) whether sociodemographic factors and pre-operative health status are associated with 15-year HRQoL changes in the surgery group. METHODS: Participants were from the non-randomized, prospective, controlled Swedish Obese Subjects study. The surgery group (N = 2007, per-protocol) underwent gastric bypass, banding or vertical banded gastroplasty, and matched controls (N = 2040) received usual obesity care. Recruitment took place in 1987-2001 and measurements (including six HRQoL scales) were administered before treatment and after 0.5, 1, 2, 3, 4, 6, 8, 10 and 15 years. Multilevel mixed-effect regression models using all observations for estimation were conducted. RESULTS: Surgical patients experienced greater 15-year improvements in perceived health and overall mood, and greater reductions in depression, obesity-related problems, and social interaction limitations than controls (all p < 0.001, adjusted for baseline differences). Effect size (ES) was classified as large only for obesity-related problems (ES = 0.82). At the 15-year follow-up, surgical patients reported better perceived health (p < 0.001) and less obesity-related problems (p = 0.020) than controls. In the surgery group, patients with baseline diabetes had smaller 15-year reductions in social interaction limitations (p < 0.001) and depression (p = 0.049) compared to those without baseline diabetes. Although surgical patients with a history of psychiatric disorder reported lower HRQoL than those without such history over the 15-year follow-up, there were no significant differences in the long-term improvements between the two groups (p = 0.211-0.902). CONCLUSIONS: Over 15 years, surgical patients experienced more positive development of HRQoL compared to those receiving usual care. This difference was large for obesity-related problems, but otherwise the differences were small. Patients with pre-operative diabetes might be at increased risk for smaller long-term HRQoL improvements.