Diabetes outcomes do not differ for patients treated with a primary care provider who is either a physician, nurse practitioner (NP), or physician assistant (PA), according to a study published online Nov. 20 in the Annals of Internal Medicine.
Primary care provided by nurse practitioners (NPs) and physician assistants (PAs) has been proposed as a solution to expected workforce shortages. To examine potential differences in intermediate diabetes outcomes among patients of the physician, NP, and PA primary care providers (PCPs).
The relationship between the profession of the PCP (the provider the patient visited most often in 2012) and both continuous and dichotomous control of hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and low-density lipoprotein cholesterol (LDL-C) was examined on the basis of the mean of measurements in 2013.
Inverse probability of PCP type was used to balance cohort characteristics. Hierarchical linear mixed models and logistic regression models were used to analyze continuous and dichotomous outcomes, respectively.
George L. Jackson, Ph.D., from the Durham Veterans Affairs Health Care System in North Carolina, and colleagues used data from the U.S. Department of Veterans Affairs (VA) for 368,481 adult patients with diabetes treated pharmaceutically at 568 VA primary care facilities.
The PCPs were physicians (n = 3487), NPs (n = 1445), and PAs (n = 443) for 74.9%, 18.2%, and 6.9% of patients, respectively. The difference in HbA1c values compared with physicians was −0.05% (95% CI, −0.07% to −0.02%) for NPs and 0.01% (CI, −0.02% to 0.04%) for PAs.
For SBP, the difference was −0.08 mm Hg (CI, −0.34 to 0.18 mm Hg) for NPs and 0.02 mm Hg (CI, −0.42 to 0.38 mm Hg) for PAs. For LDL-C, the difference was 0.01 mmol/L (CI, 0.00 to 0.03 mmol/L) (0.57 mg/dL [CI, 0.03 to 1.11 mg/dL]) for NPs and 0.03 mmol/L (CI, 0.01 to 0.05 mmol/L) (1.08 mg/dL [CI, 0.25 to 1.91 mg/dL]) for PAs. None of these differences were clinically significant.
NPs and PAs as primary care providers
The researchers found that 74.9, 18.2, and 6.9% of patients had primary care providers who were physicians, NPs, and PAs, respectively. Compared with those treated by physicians, the differences in hemoglobin A1c values were −0.05 and 0.01% for patients treated by NPs and PAs, respectively.
For systolic blood pressure, the corresponding differences were −0.08 and 0.02 mm Hg. The corresponding differences were 0.01 and 0.03 mmol/L for low-density lipoprotein-cholesterol. These differences were not clinically significant.
"In conclusion, we found no clinically significant differences in intermediate diabetes outcomes," the authors write. "As a result, this study provides further evidence that using NPs and PAs as primary care providers may represent a mechanism for expanding access to primary care while maintaining quality standards."