Disease-specific reference case extension: management of overweight and obesity in adults

Measure utility using EQ-5D based on age, body mass index (BMI) and sex and ensure these are adjusted over time based on age and BMI. Apply utility decrements to specific events and comorbidities. (required)

The best source for utilities is a single dataset that controls for weight, comorbidity and other variables such as age and sex. If that is not available then, to avoid double-counting, ensure that the source study for weight-related utilities is controlled for comorbidity or the source study for comorbidity-related utilities is controlled for weight. (required)

Mean EQ-5D scores for each intervention in the clinical trials should be used to calibrate the mean quality-of-life treatment effect in the short-term (at trial follow-up), ensuring not to double count health-related quality-of-life improvements from the reduced incidence of progression or adverse effects. (recommended)

Capture utility decrements for treatment-related adverse effects and complications from bariatric procedures in the model. Do this by weighting the incidence rate of the adverse effect by the duration of the event. For example, include gastrointestinal adverse effects such as nausea, diarrhoea and constipation for medicines, and capture recovery time and complications for bariatric procedures. (required)

When there is weight regain after an intervention, a sensitivity analysis should be conducted to model a greater decline in utility than the increase in utility associated with the initial weight loss. (recommended)