(DCP040) EVIDENCE OF CLINICAL INERTIA FROM A RETROSPECTIVE COHORT ANALYSIS OF BASAL INSULIN INITIATION IN TYPE 2 DIABETES MELLITUS IN A CANADIAN COHORT USING ADMINISTRATIVE HEALTH DATA IN ALBERTA CANADA

Background: While type 1 diabetes is treated with insulin, pharmacological treatment of type 2 diabetes mellitus (T2DM) is a tiered approach. Typically, patients with T2DM receive metformin monotherapy as first-line treatment. Second-line therapies include other non-insulin anti-hyperglycemic agents (NIAHA). In some instances, progression to insulin in combination with NIAHA is necessary.

Currently, there is uncertainty as to whether patients with T2DM and hemoglobin A1c (HbA1c) not at target are managed according to clinical guidelines, particularly with initiation of basal insulin therapy. We aim to describe real-world patterns of basal insulin initiation in patients with T2DM and HbA1c not at target.

METHODS AND RESULTS: A retrospective cohort study was conducted using administrative health data from Alberta, Canada beginning April 1, 2009 to March 31, 2020 (case ascertainment period: April 1, 2011 to March 31, 2019). Patients were indexed on the first instance of T2DM and HbA1c not at target (7%< HbA1c < 9.5%), following the dispensation of ≥2 NIAHA. Subsequent pharmacological therapies were examined at 6 months and annually following the index date to the end of follow-up and classified as: basal insulin initiation, deceased, other treatment intensification (addition, change, or increase in dose of a NIAHA relative to previous timepoint), clinical inertia (lack of intensification of antidiabetic treatment despite evidence of inadequate glycemic control relative to previous timepoint), or no follow-up (no record of subsequent pharmaceutical data but remain in the Population Registry). Results were also stratified by baseline HbA1c values (7.1-7.5%, 7.6-8.0%, 8.1-8.5%, 8.6-9.0%, and 9.1-9.4%).

Overall, 14,433 patients were included. At one-year post-index date, 7.2% (n=1,034) initiated basal insulin, 19.0% (n=2,736) intensified with another agent, and 63.9% (n=9,217) experienced clinical inertia. By year 8 (n=7,337), basal insulin initiation increased to 36.8% (n=2,700), while those with other treatment intensification decreased to 12.3% (n=899) and 29.8% (n=2,183) remained in clinical inertia. Higher HbA1c was associated with greater proportions of insulin initiation, but not with intensification with NAIHA.

Conclusion: This real-world data examining patients with type 2 diabetes and HbA1c not at target demonstrates that clinical inertia remains a significant problem. Over 8 years of follow-up 29.8% were experiencing clinical inertia (from year 7) while basal insulin initiation was slow, increasing from 7.2% at one year to 36.8% at 8 years. Despite clinical practice guidelines recommending achieving HbA1c targets within one year, this study demonstrates that a significant number of patients in Alberta are not intensifying treatment, including initiating basal insulin, in a timely manner.