Utilization and costs by primary care provider type: Are there differences among patients of physicians, NPs, and PAs?

Problem

Although labor costs of nurse practitioners (NPs) and physician assistants (PAs) are less than those of physicians, NPs and PAs might practice in ways that increase other healthcare costs, thereby increasing total costs of care. The U.S. Veterans Affairs (VA) health care system utilizes care teams led by either a physician, NP, or PA. This study examines whether there are differences in total costs or in utilization of service types by primary care provider (PCP) profession.

Approach

The study included diabetes patients receiving primary care from the same PCP within the VA in 2012 and 2013. We examined the relationship between the profession of the PCP and inpatient, emergency department (ED), and outpatient utilization and total health care costs in 2013. We controlled for gender, age, race, ethnicity, marital status, homelessness, co-pay status, mental health diagnoses, health status, travel distance to the VA, availability of specialized diabetes services at the VA, rurality of the VA, and region in regression models. ED and outpatient outcomes were analyzed using negative binomial models. Logistic regression models were fit to a dichotomous indicator of hospitalization during 2013. To interpret results, we set a priori thresholds for clinical significance of model-estimated differences.

Findings

The sample included 368,481 patients from 568 VA facilities. PCPs were physicians, NPs, and PAs for 74.9%% (n=276,009), 18.2% (n=67,120), and 6.9% (n=25,352) of patients respectively. Patients of physicians were more likely than those of PAs or NPs to incur a hospitalization (12.1% of physician patients, 95% CI: 12.0, 12.2; 11.3% of PA patients, 95% CI: 10.9, 11.7; 11.1% of NP patients, 95% CI: 10.9, 11.4). Patients of physicians also visited the ED more frequently (0.65 visits on average for physicians, 95% CI: 0.64, 0.65; 0.57 for PAs, 95% CI: 0.56, 0.59; 0.59 for NPs, 95% CI: 0.59, 0.60). No clinically meaningful differences were observed for outpatient visit utilization. Physician patients incurred expenditures 6% greater than PA patients (95% CI: 4.0%, 8.7%) and 5% greater than NP patients (95% CI: 3.3%, 6.5%), translating to a difference of $694 and $542 dollars annually per patient, respectively.

Consequences

Using EHR data, we found greater rates of hospitalizations and ED visits and greater health care expenditures among patients of physicians compared to PAs or NPs. This study, combined with previous findings that diabetes care quality in the VA did not differ by PCP type, suggests that NPs and PAs may be safely used in VA primary care of patients with diabetes without increasing total care costs. Lower utilization and expenditures for patients with PA or NP primary care providers could contribute to large aggregate cost savings for health systems. Further research is needed to elucidate patterns leading to these cost differences.