Cost-effectiveness of add-on treatments to metformin in a Swedish setting: liraglutide vs sulphonylurea or sitagplitin.

OBJECTIVE: To evaluate long-run cost-effectiveness in a Swedish setting for liraglutide compared with sulphonylureas (glimepiride) or sitagliptin, all as add-on to metformin for patients with type 2 diabetes insufficiently controlled with metformin in monotherapy. METHODS: The IHE Cohort Model of Type 2 Diabetes was used to evaluate clinical and economic outcomes from a societal perspective. Model input data were obtained from two clinical trials, the Swedish National Diabetes Register and the literature. Cost data reflected year 2013 price level. The robustness of results was checked with one-way-sensitivity analysis and probability sensitivity analysis. RESULTS: The cost per QALY gained for liraglutide (1.2 mg) compared to SU (glimepiride 4 mg), both as add-on to metformin, ranged from SEK 226,000 to SEK 255,000 in analyzed patient cohorts. The cost per QALY for liraglutide (1.2 mg) vs sitagliptin (100 mg) as second-line treatment was lower, ranging from SEK 149,000 to SEK 161,000. Costs of preventive treatment were driving costs, but there was also a cost offset from reduced costs of complications of ∼ 20%. Notable cost differences were found for nephropathy, stroke, and heart failure. The predicted life expectancy with liraglutide increased the cost of net consumption for liraglutide. LIMITATIONS: The analysis was an ex-ante analysis using model input data from clinical trials which may not reflect effectiveness in real-world clinical practice in broader patient populations. This limitation was explored in the sensitivity analysis. The lack of specific data on loss of production due to diabetes complications implied that these costs may be under-estimated. CONCLUSIONS: Treatment strategies with liraglutide 1.2 mg improved the expected quality-of-life and increased costs when compared to SU and to sitagliptin for second-line add-on treatments. The cost per QALY for liraglutide was in the range considered medium by Swedish authorities.