Examining therapeutic inertia patterns in type 2 diabetes patients with multiple chronic conditions: Time-to-event...

Therapeutic inertia (TI) in type 2 diabetes (T2D)-delayed treatment adjustment despite elevated A1C-is often complicated by multiple chronic conditions (MCC). We examined how clinicians address TI in patients with T2D and MCC and evaluated association with patient, clinic, and neighborhood factors.

Using electronic health records from two Midwestern U.S. health systems, we identified a retrospective six-year cohort of adults with T2D, MCC, and above-target A1C (>7% [53 mmol/mol] for age < 65; >8% [64 mmol/mol] for age $\ge$ 65). Time-to-event analyses assessed factors associated with clinicians addressing TI. The event was defined as maintaining TI $\le$ 0.5 for two consecutive years indicating prescription changes occurred in more than 50% of opportunities following above-target A1C. Covariates included demographics, comorbidity, insulin use, number of diabetes drug classes, clinic rurality, and neighborhood social deprivation.

A cohort of 18,003 adults met eligibility criteria (mean age 59; 78% White). Among patients with T2D and MCC, clinicians addressed TI in 17% of cases at two-year, 31% at four-year, and 38% at five-year follow-up. Clinicians were more likely to address TI with MCC in patients experiencing greater social deprivation and being prescribed with more diabetes drug classes at baseline (p<0.05). Despite addressing TI, patients aged 18-44 had the worst glycemic control (8.3% [67 mmol/mol]) and high prevalence of depression (82%).

Therapeutic inertia varied by patient, clinic, and neighborhood factors, emphasizing the need for targeted, multifaceted interventions to reduce TI, especially among populations facing socioeconomic and mental health challenges.