Aims: This retrospective cohort study investigated whether clinical inertia, the failure to intensify treatment when required, exists in Japanese clinical practice, using the CoDiC® database. How and when patients with type 2 diabetes treated with basal insulin received treatment intensification was also described.
Materials and methods: Patients with type 2 diabetes who initiated basal insulin between 2004 and 2011 were eligible for inclusion. Patients with an HbA1c ≥7.0% (≥53.0 mmol/mol) after 180 days of basal insulin titration were eligible for intensification, and their treatment was followed for up to 1.5 years. Endpoints were time to intensification, changes in HbA1c, and insulin dose.
Results: Overall, 2351 patients initiated basal insulin treatment (mean HbA1c 9.4% [79.2 mmol/mol]), and 1279 patients were eligible for treatment intensification (HbA1c ≥7.0% [≥53.0 mmol/mol]) after the 180-day titration period. During the 1.5-year follow-up period (beyond the 180-day titration period), 270 (21%) of these patients received treatment intensification. In patients receiving treatment intensification, mean HbA1c decreased from 8.6 to 8.2% (70.5 to 66.1 mmol/mol) at end of follow-up. Treatment was intensified using bolus insulin in 126 (47%) patients and with premixed insulin in 144 (53%) patients. The estimated probability of intensifying treatment during the 12 months after recording HbA1c ≥7.0% (≥53.0 mmol/mol) was 22.8%, and 27.5% after 17 months. Mean end-of-follow-up daily insulin dose was 35.11 units for basal-bolus compared with 20.70 units for premix therapy.
Conclusions: This study suggests clinical inertia exists in basal insulin-treated patients with type 2 diabetes in Japan. Strategies are needed to increase the number of patients undergoing therapy intensification and to reduce the delay in intensification in Japan.