OBJECTIVES : Randomized clinical trials have suggested dose differences between basal insulins. In real-world, however, various factors may impact dose requirements and therefore the economic burden between basal insulin analogues. This study aimed to assess, how the real-world relative insulin doses change after switching basal insulin to insulin glargine 300 U/ml (Gla-300).

METHODS : The data on purchased insulin doses was obtained from the Finnish national reimbursement registry. Population consisted of 12 549 patients with type 1 and type 2 diabetes who started or switched to Gla-300 in 2016. The insulin purchases were retrospectively observed for 6 and 12 months after the initiation of Gla-300, and analysed for basal insulin therapy preceding Gla-300 and type of diabetes. Real-world dose differences were compared with those of insulin glargine 100 U/ml (Gla-100) and insulin detemir.

RESULTS : In all patients who switched (n=6 131), the 6 month/12 month dose difference between Gla-300 and Gla-100 was 3 %/0 %, and between Gla-300 and insulin detemir -11/-16 %, respectively. The dose difference between Gla-300 and Gla-100 after 6 month/12 month follow-up was -1 %/-6 % in patients with type 1 and 4 %/1 % in type 2 diabetes, respectively. The dose difference between insulin Gla-300 and insulin detemir, after 6 month/12 month follow-up was -15 %/-20 % in patients with type 1 and -11 %/-15 % in type 2 diabetes, respectively.

CONCLUSIONS : In this real-life study, negligible differences were seen between Gla-300 and Gla-100. Gla-300 doses were lower than insulin detemir. This study provides the decision makers supplementary information to clinical trial data which could be utilised in the assessment of the drug prices and future treatment costs between basal insulins.