Factors associated with clinical inertia in type 2 diabetes mellitus patients treated with metformin monotherapy.

To assess demographic and clinical characteristics associated with clinical inertia in a real-world cohort of type 2 diabetes mellitus patients not at hemoglobin A1c goal (<7%) on metformin monotherapy. Adult (≥18 years) type 2 diabetes mellitus patients who received care at Massachusetts General Hospital/Brigham and Women's Hospital and received a new metformin prescription between 1992 and 2010 were included in the analysis. Clinical inertia was defined as two consecutive hemoglobin A1c measures ≥7% ≥3 months apart while remaining on metformin monotherapy (i.e. without add-on therapy). The association between clinical inertia and demographic and clinical characteristics was examined via logistic regression. Of 2848 eligible patients, 43% did not achieve a hemoglobin A1c goal of <7% 3 months after metformin monotherapy initiation. A sub-group of 1533 patients was included in the clinical inertia analysis, of which 36% experienced clinical inertia. Asian race was associated with an increased likelihood of clinical inertia (OR = 2.43; 95% CI = 1.48-3.96), while congestive heart failure had a decreased likelihood (OR = 0.58; 95% CI = 0.32-0.98). Chronic kidney disease and cardiovascular/cerebrovascular disease had weaker associations but were directionally similar to congestive heart failure. Asian patients were at an increased risk of clinical inertia, whereas patients with comorbidities appeared to have their treatment more appropriately intensified. A better understanding of these factors may inform efforts to decrease the likelihood for clinical inertia.