OBJECTIVES: This study assessed the cost-effectiveness of type 1 diabetic patients treated with insulin detemir based basal-bolus therapy versus neutral protamine Hagedorn (NPH) insulin based basal-bolus therapy in a Belgian setting using results obtained from a meta-analysis of three clinical trials. The meta-analysis demonstrated an improvement for detemir over NPH in HbA1c (0.13% points lower), lower body mass index (BMI) (0.21 kg.m-2) and a 4% decrease in hypoglycemic events, when used in combination with either insulin aspart or human soluble insulin. METHODS: A published and validated computer simulation model for diabetes (the CORE Diabetes Model) was used to project short-term results obtained from the fixed-effects meta-analysis to estimate long-term clinical and cost outcomes for detemir based basal-bolus therapy versus NPH based basal-bolus therapy using Belgian specific patient characteristics, mortality rates and costs of treating complications derived from published sources. Probabilities of complications were derived from landmark clinical and epidemiological studies. Total direct costs (complications + treatment costs) for each arm were projected over patient lifetimes. Future costs and clinical benefits were discounted at respectively 3% and 1.5% per annum in line with published guidance. RESULTS: Short-term therapy benefits associated (improved glycemic control, decreased hypoglycemic events and lower BMI) with detemir based basal-bolus therapy led to fewer diabetes-related complications, and a resulting increase in quality-adjusted life expectancy of 0.173 quality-adjusted life years (QALYs) (7.296±0.111 versus 7.123±0.115 QALYs). Higher therapy costs for detemir versus NPH resulted in an increased lifetime costs/patient of €5,075 (€86,602±1730 versus €81,527) and a resultant incremental cost-effectiveness ratio of €29,288 per QALY gained. CONCLUSION: The clinical benefits demonstrated in the meta-analysis for detemir over NPH in basal-bolus therapy predict long-term outcome improvements which reduce diabetes related complications, increased patient quality of life and result in an incremental cost-effectiveness ratio which represents good value for money in Belgium.