OBJECTIVES: A meta-analyses of the results from three clinical trials in type 1 diabetes patients showed that insulin detemir (IDet) based basal-bolus treatment compared to neutral protamine Hagedorn (NPH) insulin based basal-bolus therapy led to improved HbA1c (0.13% points lower), a decrease in hypoglycaemic events (by 4%) and lower body mass index (BMI) (0.21 kg.m-2). METHODS: A published, validated, peer-reviewed computer simulation model of diabetes (the CORE Diabetes Model) was used to project short-term results obtained from the fixed-effects (weighted average) meta-analysis to long-term clinical and cost outcomes (including life expectancy, quality adjusted life expectancy, incidence of complications, and direct medical costs) for IDet versus NPH in type 1 diabetes patients, when used in combination with either insulin aspart (IAsp) or human soluble insulin (HSI) as the bolus component of therapy. Probabilities of complications were derived from landmark clinical and epidemiological studies and the costs of treating complications in Italy were retrieved from published sources. Total direct costs (complications + treatment costs) for each arm were projected over patient lifetimes from an Italian Heath Service perspective. Both costs and clinical outcomes were discounted at 3% annually. RESULTS: Improved glycaemic control, decreased hypoglycaemic events and lower BMI with IDet-based basal/bolus therapy led to fewer diabetes-related complications, an increase in quality-adjusted life expectancy of 0.185 quality-adjusted life years (QALYs) (7.71±0.09 versus 7.53±0.09 QALYs), increased total lifetime costs/patient of €5,680 (€104,234±2354 versus €98,554±2124), and an incremental cost-effectiveness ratio of €30,704 per QALY gained. Results were stable under variation in a range of reasonable assumptions. CONCLUSION: The increased cost of therapy for IDet versus NPH is partly offset by reductions in the treatment costs of complications and, given the associated clinical benefits, leads to a cost-effectiveness ratio which falls within a range generally considered to represent excellent value for money (