Direct healthcare costs and clinical outcomes after insulin initiation in patients with type 2 diabetes mellitus in Spain: 24-month follow-up data from the INSTIGATE study

Background and objective: The INSTIGATE study assessed healthcare costs and clinical out comes in patients with type 2 diabetes mellitus starting insulin therapy in Spain over a 24-month follow up period. Material and methods: This was an observational, non-interventional, prospective, multicenter study. Costs incurred in the previous 6 months were assessed at each visit. Results: A total of 172 patients with a mean body mass index of 29.6 kg/m(2), a mean [standard deviation] duration of diabetes of 10.9 [7.0] years and a hemoglobin A(1c) value of 9.2% [1.5%] were followed up for at least 12 and up to 24 months. Direct costs were assessed from the perspective of the Spanish healthcare system. Long/intermediate-acting insulin alone was started in 116 patients (67.4%). After 6, 12, and 24 months of insulin treatment, mean [SD] intraindividual changes from baseline in hemoglobin A(1c) were -1.9% [1.65%], -1.6 [1.73%], and -1.5% [1.76%] respectively. Mean (median) total diabetes-related healthcare costs per patient increased from (sic)659 ((sic)527) to (sic)1.085 ((sic)694) 6 months after insulin initiation, decreased to (sic)646 ((sic)531) after 12 months, and increased again after 24 months to (sic)667 ((sic)539). Insulin/oral antidiabetics, primary/specialized care, and blood glucose monitoring accounted for 41%, 26%, and 19% of total cost at 24 months respectively. Conclusions: Clinical parameters of these patients with type 2 diabetes mellitus improved following insulin initiation. After a temporary increase, direct healthcare costs of diabetes care returned to baseline values at the end of the follow-up period. (C) 2012 SEEN. Published by Elsevier Espana, S.L. All rights reserved.