Aims: Clinical obesity services in public hospitals and private clinics offer more intensive treatments and care for obesity, with varying success. We aimed to develop a decision aid tool using “real-world” data within the Australian health system to predict weight loss after bariatric surgery and non-surgical care.
Materials and methods: We analysed de-identified patient record data (aged 16+years) of initial review between 2015 and 2020 with 6-months (n=219) and 9 or 12-months (n=153) follow-ups at eight clinical obesity services nationwide. The primary outcome was percentage weight loss in the first 6-months and 9 or 12-months after initial review. Predictors were selected by statistical evidence (p<0.20), effect size (±2%), and clinical judgment. Multiple linear regression and bariatric surgery were used to create simple predictive models. The accuracy of predictions was measured using percentage of predictions ±5% of the observed value, and sensitivity and specificity for predicting target weight loss of 5% for non-surgical care and 15% for bariatric surgery.
Results: Bariatric surgery resulted in greater observed weight loss than non-surgical care at 6-months (19% vs. 5%) and 9 or 12-months (22% vs. 5%). The predicted weight loss at 6-months was: 6%,+15% if bariatric surgery,+2% if T2D, –3% if ≥10 alcohol drinks/week, –2% if current smoker,–2% if depression history,–2% if eating disorder history, and–1% if anxiety history. Accuracy was 55% (120/219), sensitivity was 53%, and specificity was 78%. The predicted weight loss at 9-12-months was: 5%,+16% if bariatric surgery,+6% if eating disorder history,+5% if T2D,–3% if osteoarthritis,–3% if sleep disorder, and–2% if depression history. Accuracy was 50% (77/153), sensitivity was 85%, and specificity was 51%.
Conclusions: The DACOS scoring system can help clinicians set realistic goals for obesity management by considering several predictors of weight loss. Further research is needed to improve the predictive power of the scoring tool.