Background: Pre-operative predictive measures of post-metabolic surgery success would facilitate a more refined evidence-based selection of patients. This study aimed at identifying those clinical and psycho-social predictors of success (defined as weight-loss) following metabolic surgery.
Methods: Pre-operative data including IWQOL-Lite questionnaire (a validated self-reported 31-item measure of physical function, self-esteem, sexual life, public distress and work related domains of obesity-specific quality of life (QOL)) scores transformed to a 0100 scale, where a score of 100 represents the best health-related QOL (HRQOL), were obtained for 26 patients who had completed 1 year follow-up post-metabolic surgery at University Hospitals Coventry and Warwickshire. Comparisons were made between pre-operative characteristics from two subgroups: patients with <30, and >50% excess weight lost 1 year post-operatively (towards an ideal BMI 25 kg/m2 (EWL-1 year)). Statistical analyses were done for pre-operative variables and EWL-1 year. Results are reported as (mean) and (S.D.). P<0.05 is considered statistically significant.
Results: Comparisons between the subgroups with lower and higher EWL-1 year values (n=12 and 9 respectively) showed no significant differences in pre-operative HRQOL scores for all QOL domains. Only pre-operative BMI and EWL-1 year had significant correlation (r=0.499, P=0.009). Pre-operatively, BMI showed a significant negative correlation with public distress HRQOL (r=−0.54, P=0.005) and self-esteem related HRQOL (r=−0.409 P=0.041). Multivariate linear regression analysis with age, sex, BMI and HRQOL scores as independent variables and EWL-1 year as a dependent variable, revealed that pre-operative BMI had a significant independent association with EWL-1 year (β=0.70, P=0.01).
Conclusion: We show a significant, independent and direct relationship between pre-operative BMI and excess weight-loss one year following metabolic surgery, although pre-operative QOL measures were not predictive of EWL-1 year. It remains possible that pre-op QOL may predict improved psycho-social function post metabolic surgery.