Fifteen-year changes in health-related quality of life after bariatric surgery and non-surgical obesity treatment

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. 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. 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). 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.