Utility Decrements Associated with Adult Overweight and Obesity in Australia: A Systematic Review and Meta-Analysis.

OBJECTIVE The aim was to conduct a systematic review and meta-analysis of health state utility decrements associated with overweight and obesity in adults 18 years and over, for use in modelled economic evaluations in Australia. METHODS A systematic review was conducted in nine databases to identify studies that reported health state utility values by weight status. Random-effects meta-analysis was used to synthesise average utility decrements (from healthy weight) associated with overweight, all obesity and obesity classes 1, 2 and 3. Heterogeneity surrounding utility decrements was assessed via sub-group analysis, random-effects meta-regression and sensitivity analyses. RESULTS Twelve studies were found for which data were used to synthesise utility decrements, estimated as overweight = 0.020 (95% confidence interval 0.010-0.030), all obesity = 0.055 (0.034-0.076), obesity class 1 = 0.047 (0.017-0.077), class 2 = 0.072 (0.028-0.116) and class 3 = 0.084 (0.039-0.130). There was considerable heterogeneity in our results, which could be accounted for by the different ages and utility instruments used in the contributing studies. CONCLUSIONS Our results demonstrate that elevated weight status is associated with small but statistically significant reductions in utility compared with healthy weight, which will result in reduced quality-adjusted life years when extrapolated across time and used in economic evaluations.