Influence of treatment intensification on A1C in patients with suboptimally controlled type 2 diabetes after 2 oral antidiabetic agents

BACKGROUND: In the United States, more than 50% of patients with type 2 diabetes mellitus (T2DM) have hemoglobin A1c (A1c) levels that fail to achieve the recommended target of <7.0%. Of these, 30%-45% have an A1c>9.0%, the threshold for poorly controlled T2DM per National Committee for Quality Assurance (NCQA) measures. Treatment inertia is a known challenge. However, recent treatment intensification patterns and outcomes after treatment fails 2 classes of oral antidiabetic agents (OADs) are not well understood. OBJECTIVE: To characterize treatment intensification patterns and glycemic control outcomes in patients with A1c≥7.0% on 2 OADs. METHODS: A retrospective cohort study was conducted in patients with T2DM from a regional health plan claims dataset augmented with A1c results between January 1, 2010, and March 31, 2017. Patients were identified with an A1c≥7.0% (baseline), while on 2 OADs, and whose treatment was intensified with basal/biphasic insulin (insulin), glucagon-like peptide-1 receptor antagonist (GLP-1RA), or a third OAD within 365 days after the baseline A1c≥7.0%. Patients had at least 1 A1c value 60-365 days (follow-up period) after treatment intensification. The proportion of patients with an A1c<7.0% and <9.0% at follow-up were identified by therapeutic intensification strategy. Odds ratios for achieving A1c<7.0% and <9.0% were calculated. RESULTS: 1,226 patients were included in the analysis, and 33.5% of the patients had a baseline A1c≥9.0%. 24% of patients received insulin; 16% received GLP-1RA; and 60% received a third OAD for the treatment intensification. Overall, 26.0% achieved A1c<7.0% and 76.1% of patients achieved <9.0%, with a median follow-up of 119 days. The proportion of patients intensified with insulin who had an A1c≥9.0% at follow-up was 34.6% versus 53.2% at baseline (P<0.01). The corresponding percentages for those intensified with a GLP-1RA and OAD were 21.6% versus 27.1% (P=0.24) and 20.1% versus 27.3% (P<0.01). After controlling for baseline characteristics, the odds ratio (95% CI) of achieving A1c<7.0% and <9.0% was 2.05 (1.45-2.90) for GLP-1RA and 0.92 (0.61-1.40) for OAD. The association between goal attainment and GLP-1RA versus OAD intensification was influenced by the time to the A1c follow-up and baseline A1c. CONCLUSIONS: Treatment intensification was associated with improved glycemic control in patients after therapy failed 2 OADs. Patients with higher A1c at baseline were likely to initiate insulin, which was associated with a greater drop in A1c. GLP-1RA was associated with a higher likelihood of achieving NCQA-suggested glycemic control compared with a third OAD. However, the association varied by the follow-up period. These findings are important to health plans seeking to improve patient outcomes as reflected in high performance on NCQA diabetes quality measures by promoting effective and timely treatment intensification.