Validation of a De Novo Microsimulation Model to Assess the Cost-Effectiveness of Semaglutide 2.4MG in Adults With Overweight or Obesity

OBJECTIVES: The reliability of a decision model to guide decision-making depends on its ability to accurately predict patient outcomes. We present results of a preliminary external validation of a MicroSimulation Model (MSM) that was developed to compare the cost-effectiveness of semaglutide 2.4mg with diet and exercise in adults with overweight or obesity.

METHODS: We updated a 2020 systematic literature review of economic models in overweight and obesity and conducted additional targeted searches to identify suitable sources and outcomes to validate against MSM in overweight/obese population with normoglycaemia/prediabetes. We extracted baseline characteristics and cardiovascular (CV) and mortality outcomes, where these were closely matched with MSM. We performed dependent (sources used in MSM) and independent (sources not used in MSM) validation. The extent of concordance between predicted and observed outcomes was assessed using coefficient of determination (R²), mean absolute percentage error (MAPE), root mean square percentage error (RMSPE), and mean squared log of accuracy ratio (MSLAR).

RESULTS: Ninety-three potential independent validation sources were identified from 6,122 screened records, of which five studies reported CV and mortality outcomes that were closely matched with MSM (Number of endpoints=62). The dependent validation of CV and mortality outcomes (N=18), based on QRisk3 risk equation, showed good linear correlation with observed outcomes, with some slight overprediction, resulting in high R² (0.99; slope=1.11) and low MAPE (8.27%), RMSPE (8.72%) and MSLAR (1.27%). The independent validation also showed good linear correlation with observed outcomes, with some degree of under-prediction. The resulting R² was 0.84 (slope=0.88); mean error estimates were 37.28%, 48.69%, and 11.26% for MAPE, RMSPE, and MSLAR, respectively.

CONCLUSIONS: Preliminary validation of MSM showed good concordance with dependent and independent sources, suggesting the model accurately predicts obesity-related events in overweight/obese population with normoglycaemia/prediabetes. Further validation of MSM is underway in type 2 diabetes population.