Factors associated with seeking physician care by medicare beneficiaries who receive all their primary care from nurse practitioners

Background: A shortage of primary care physicians has led to the alternative strategy of nurse practitioners (NPs) as primary care providers for the growing elderly population. Many states have implemented policies that allow NPs to practice independently with no physician oversight. Little is known about the continuity of primary care provided by NPs. Objective: To examine rate and correlates of switching from exclusive NP primary care to receiving some or all primary care from physicians. Design: A retrospective cohort study. Participants: Medicare beneficiaries (n = 38 618) with diabetes, congestive heart failure, or chronic obstructive pulmonary disease who received all their primary care from NPs in 2007. Main Measures: Multivariable logistic regression model was used to assess patient and disease characteristics associated with switching from sole NP primary care in 2007 to receiving some or all primary care from physicians between 2008 and 2010. Results: Of elderly patients receiving all their primary care from NPs in 2007, 53.8% switched to receiving some or all primary care from physicians in 2008-2010. The switching patients had less comorbidity before the switch and were more likely to reside in metropolitan areas, ZIP code areas with high education or states with the most restriction on NP scope of practice. In multivariable analyses, significant predictors of switching included one of the following within 30 days before the switch: emergency room visits (odds ratio [OR] = 1.55, 95% confidence interval [CI] = 1.44-1.68), hospitalization (OR = 1.13, 95% CI = 1.02-1.25), new diagnosis of heart attacks (OR = 5.52, 95% CI = 4.33- 7.02), pneumonia (OR = 4.84, 95% CI = 3.71-6.32), atrial fibrillation (OR = 3.99, 95% CI = 2.93-5.44), stroke (OR = 2.94, 95% CI = 2.31-3.74), or cancer (OR = 2.65, 95% CI = 1.94-3.63). Conclusions: About half of Medicare patients under exclusive NP primary care switched to physicians for some or all primary care over a 3-year period. Future study is needed to understand the reasons for switching.