OBJECTIVES: To identify recent data describing the long-term risk of complications in patients with type 1 diabetes mellitus (T1DM), and their association with glycosylated haemoglobin (HbA1c) and other risk factors, and to select complications and related data for inclusion in a new cost-utility model for T1DM.
METHODS: A systematic review was performed. The following electronic databases were searched (1 January 2003-27 July 2011): MEDLINE, MEDLINE In-Process, EMBASE, and the Cochrane Library, including the Health Technology Assessment (HTA) database. Relevant clinical guidelines and HTA documentation were also searched.
RESULTS: A total of 4,846 titles were screened; 281 reports of 72 unique studies were included for qualitative synthesis. Multiple reports were identified for several studies, including the Diabetes Control and Complications Trial and the Epidemiology of Diabetes Interventions and Complications follow-up study (DCCT/EDIC), the Epidemiology of Diabetes Complications (EDC) study, the Finnish Diabetic Nephropathy (FinnDiane) Study, the Wisconsin Epidemiologic Study of Diabetic Retinopathy, the EURODIAB type 1 complications study, and several other large observational and registry studies. Data were extracted for 57 T1DM complications in adults and 20 in children and adolescents. Complications were selected for inclusion in the cost-utility model where there was evidence for a statistical association with T1DM and HbA1c levels, an impact on mortality, and an expected impact on costs and/or health-related quality of life. The following complications were selected: cardiovascular disease, peripheral neuropathy, renal disease, retinopathy, cataract, hypoglycemia, ketoacidosis and adverse birth outcomes.
CONCLUSIONS: Since 2003, 281 reports of 72 studies (including many large, observational studies) have been published. These reports have substantially increased the available evidence describing complications in T1DM patients. The DCCT/EDIC studies uniquely provide long-term follow-up (now more than 23 years) of patients managed using strategies that are reasonably representative of contemporary T1DM management.
