Volume 50 | Number 2 | April 2015

Abstract List

Guy David PhD, Candace Gunnarsson Ed.D., Philip A. Saynisch A.B., Ravi Chawla M.B.A., Somesh Nigam Ph.D.


To assess whether adoption of the patient‐centered medical home () reduces emergency department () utilization among patients with and without chronic illness.

Data Sources

Data from approximately 460,000 Independence Blue Cross patients enrolled in 280 primary care practices, all converting to status between 2008 and 2012.

Research Design

We estimate the effect of a practice becoming ‐certified on visits and costs using a difference‐in‐differences approach which exploits variation in the timing of certification, employing either practice or patient fixed effects. We analyzed patients with and without chronic illness across six chronic illness categories.

Principal Findings

Among chronically ill patients, transition to status was associated with 5–8 percent reductions in utilization. This finding was robust to a number of specifications, including analyzing avoidable and weekend visits alone. The largest reductions in visits are concentrated among chronic patients with diabetes and hypertension.


Adoption of the model was associated with lower utilization for chronically ill patients, but not for those without chronic illness. The effectiveness of the model varies by chronic condition. Analysis of weekend and avoidable visits suggests that reductions in utilization stem from better management of chronic illness rather than expanding access to primary care clinics.