Diabetes Mellitus Care Provided by Nurse Practitioners vs Primary Care Physicians

OBJECTIVES: To compare processes and cost of care of older adults with diabetes mellitus cared for by nurse practitioners (NPs) with processes and cost of those cared for by primary care physicians (PCPs). DESIGN: Retrospective cohort study. SETTING: Primary care in communities. PARTICIPANTS: Individuals with a diagnosis of diabetes mellitus in 2009 who received all their primary care from NPs or PCPs were selected from a national sample of Medicare beneficiaries (N = 64,354). MEASUREMENTS: Propensity score matching within each state was used to compare these two cohorts with regard to rate of eye examinations, low-density lipoprotein cholesterol (LDL-C) and glycosylated hemoglobin (HbA1C) testing, nephropathy monitoring, specialist consultation, and Medicare costs. The two groups were also compared regarding medication adherence and use of statins, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (for individuals with a diagnosis of hypertension), and potentially inappropriate medications (PIMs). RESULTS: Nurse practitioners and PCPs had similar rates of LDL-C testing (odds ratio (OR) = 1.01, 95% confidence interval (CI) = 0.94-1.09) and nephropathy monitoring (OR = 1.05, 95% CI = 0.98-1.03), but NPs had lower rates of eye examinations (OR = 0.89, 95% CI = 0.84-0.93) and HbA1C testing (OR = 0.88, 95% CI = 0.79-0.98). NPs were more likely to have consulted cardiologists (OR = 1.29, 95% CI = 1.21-1.37), endocrinologists (OR = 1.64, 95% CI = 1.48-1.82), and nephrologists (OR = 1.90, 95% CI = 1.67-2.17) and more likely to have prescribed PIMs (OR = 1.07, 95% CI = 1.01-1.12). There was no statistically significant difference in adjusted Medicare spending between the two groups (P = .56). CONCLUSION: Nurse practitioners were similar to PCPs or slightly lower in their rates of diabetes mellitus guideline-concordant care. NPs used specialist consultations more often but had similar overall costs of care to PCPs.