Abstract

Objective: Clinical inertia has been identified as a critical barrier to glycemic control in type 2 diabetes. We assessed the relationship between patients' initial medication adherence and subsequent regimen intensification among patients with persistently elevated HbA1c levels.

Objective: Research Design & Methods: We analyzed an inception cohort of 2065 insured patients with type 2 diabetes newly started on hypoglycemic therapy and followed for at least three years between 1992 and 2001. Medication adherence was calculated by dividing the number of dispensed by prescribed doses for the first-prescribed hypoglycemic drug for the period between medication initiation and the next elevated HbA1c result measured at least three months later; intensification was defined as a dose increase or the addition of a second hypoglycemic agent.

Results: Patients were 55.4 (12.2) years old, 53% were men, and 19% were black. Baseline medication adherence was 79.8 (19.3)%. Patients in the lowest quartile of adherence were significantly less likely to have their regimens increased within 12 months of their first elevated HbA1c compared to patients in the highest quartile (27% vs. 37% with increased regimens if HbA1c elevated, p < 0.001). In multivariate models adjusting for patient demographic and treatment factors, patients in the highest adherence quartile had 53% greater odds of medication intensification after an elevated HbA1c [95% CI: 1.11-1.93, p = 0.01].

Conclusions: Among insured diabetic patients with elevated HbA1c, level of medication adherence predicted subsequent medication intensification. Poor patient self-management behavior increases therapeutic clinical inertia.