Volume 52 | Number 6 | December 2017

Abstract List

Maria C. Raven M.D., M.P.H., M.Sc., David Guzman M.S., Alice H. Chen M.D., John Kornak Ph.D., Margot Kushel M.D.


Out‐of‐network emergency department (ED) use, or use that occurs outside the contracted network, may lead to increased care fragmentation and cost. We examined factors associated with out‐of‐network use among Medicaid beneficiaries.

Data Sources and Study Setting

Enrollment, claims, and encounter data for adult Medi‐Cal health plan members with 1+ visits and complete Medicaid eligibility during the study period from 2013 to 2014.

Study Design

We analyzed the data to identify factors associated with out‐of‐network use classified by mode of arrival (ambulance vs. nonambulance).

Data Extraction Methods

We extracted encounter, ambulance, and census data and linked them together based on visit date.

Principal Findings

Of 11,143 visits, 6,808 (61.1 percent) were out‐of‐network. The number of hours the study was on ambulance diversion increased the odds of out‐of‐network visits for the 3,365 (30.2 percent) visits arriving by ambulance. For all visit types, assignment to a primary care clinic at the in‐network hospital and having had any primary care visit during the study period decreased the odds of out‐of‐network care. Individuals were more likely to go out‐of‐network for care if they lived in neighborhoods containing out‐of‐network s.


There are a number of factors related to out‐of‐network use, including the proximity and density of out‐of‐network s, race and ethnicity, a prior history of out‐of‐network use, and individuals’ connection to primary care. s that serve Medicaid beneficiaries may need to explore alternative sites and modalities of care as alternatives to the , and consider their ability to absorb large numbers of out‐of‐network visits given already limited capacity.