Psychosocial predictors of quality of life and weight loss two years after bariatric surgery: Results from the Toronto Bari-PSYCH study

Objectives: Studies exploring the impact of pre-surgery psychiatric status as a predictor of health related quality of life (QOL) after bariatric surgery have been limited to short-term follow-up and variable use of psychosocial measures. We examined the effect of pre-operative psychiatric factors on QOL and weight loss 2-years after surgery. Methods: 156 patients participated in this prospective cohort study, the Toronto Bariatric Psychosocial Cohort Study, between 2010 and 2014. Patients were assessed pre-surgery for demographic factors, weight, psychiatric diagnosis using the MINI International Neuropsychiatric Interview and symptom measures for QOL, depression and anxiety at pre-surgery and at 1 and 2 years post-surgery. Results: At 2-years post-bariatric surgery, patients experienced a significant decrease in mean weight (-48.43 kg, 95% [-51.1, -45.76]) and an increase only in physical QOL (+ 18.91, 95% [17.01, 20.82]) scores as compared to pre-surgery. Multivariate regression analysis identified pre-surgery physical QOL score (p < 0.001), younger age (p = 0.005), and a history of a mood disorder as significant predictors of physical QOL. Only a history of a mood disorder (p = 0.032) significantly predicted mental QOL (p = 0.006). Presurgery weight (p < 0.001) and a history of a mood disorder (p = 0.047) were significant predictors of weight loss 2-years post-surgery. Conclusions: Bariatric surgery had a sustained impact on physical QOL but not mental QOL at 2-years postsurgery. A history of mood disorder unexpectedly increased physical QOL scores and weight loss following surgery. Further research is needed to determine if these results are due to bariatric surgery candidate selection within this program.