Economic evaluation of orlistat in overweight and obese patients with type 2 diabetes mellitus.

OBJECTIVE: To estimate the economic value of pharmacological treatment of type 2 diabetes mellitus in overweight and obese patients using orlistat in addition to standard diabetes therapy (i.e., a sulphonlyurea, metformin or insulin) and weight management strategies as compared with standard diabetes therapy and weight management strategies alone in a US-based healthcare setting. The perspective of the study was from the viewpoint of a US healthcare provider. DESIGN AND
SETTING: Markov state transition model simulating diabetes-related complications and mortality for a period of 11 years. Patients were modelled to continue orlistat therapy for a 52-week period, assuming a 3-year period of weight regain where after 3 years bodyweight would match that of the placebo group. The impact of orlistat on glycosylated haemoglobin (HbA(1c)) values was evaluated directly using data from four randomised, placebo-controlled, 1-year trials of orlistat in overweight or obese adults with type 2 diabetes who also received standard diabetes pharmacotherapy and intensive lifestyle modification. Incidence rates of micro- and macrovascular complications associated with type 2 diabetes and the estimated relative reduction in incidence rates associated with a decrease in mean updated HbA(1C) values were derived from the United Kingdom Prospective Diabetes Study (UKPDS) estimates for a reference population of male patients, 52 years of age. US cost estimates were derived from published sources and presented in 2001 US dollars. Discounting of 3% was applied. Probabilistic sensitivity analysis was applied to evaluate the robustness of the results of the persistence of the effect of orlistat after treatment. MAIN OUTCOME MEASURES: Average costs and event-free life-years gained during the 11-year period expressed as the incremental costs divided by the incremental gain in life expectancy.
RESULTS: Treatment with orlistat, 120 mg three times daily, increased event-free life expectancy by 0.13 years over an 11-year period. Average treatment costs were estimated to be 19,987 US dollars in the orlistat group compared with 18,865 US dollars in the group that received diabetes medication and weight management alone. This translated into a cost-effectiveness ratio of 8327 US dollars per event-free life-year gained.
CONCLUSION: Adding orlistat as a pharmacological treatment to conventional diabetes and weight management approaches seems to be a cost-effective treatment option for overweight and obese patients with type 2 diabetes.