Article Title

The Impact of Narrow Provider Networks on Patterns of Care

Publication Date



narrow provider networks, health care utilization


Background/Aims: Our objective is to determine factors affecting choice of narrow provider network plans, and whether care covered by a narrow network preferred provider organization (PPO) plan differs from care provided in a plan with a broader PPO network. Narrow provider networks, when built around a single vertically integrated system, hold the potential for improvements in clinical care due to better information flow among providers, reduced duplication of tests and a more holistic knowledge of the patient.

Methods: The study sample includes employees enrolled through a private health insurance exchange who had coverage through one of the 93 employers offering network choice beginning in 2013. We follow enrollees through 2014 to identify the short-term impact of narrow network choice on patterns of health care delivery. Using claims data (2010–2014) from a regional health insurer offering a single-carrier private insurance exchange for employment-based coverage, we predict enrollment in a narrow network plan option and use both instrumental variable methods and difference-in-differences methods to identify the association between narrow network enrollment and future patterns in health care delivery. Network options include a broad PPO network covering 95% of the primary care physicians in the region, and four narrow provider networks. Each narrow network is built around a single vertically integrated delivery system.

Results: Preliminary results indicate a statistically significant decline in both primary care and specialty care visits. The probability of accessing any care during the year was not impacted by narrow network enrollment, but overall utilization levels declined for those enrolled in a narrow network. There were no associations between narrow network enrollment and the risk of hospital-based care (emergency department visits, avoidable emergency department visits, inpatient admission) and no associations with the probability of preventive cancer screening (breast, cervical, colorectal).

Conclusion: It is encouraging to see reductions in specialty care visits without increases in emergency department or inpatient care or decreases in the probability of accessing any care in the year. While reductions in primary care visits indicate a need for caution, the pattern of reduced utilization may be a result of better provider knowledge of the patient due to care concentrated within a single care system.




July 5th, 2016


August 12th, 2016