Related Experiment Video
Updated: Apr 29, 2026
Inverse Probability of Treatment Weighting Propensity Score using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
The association between community-level insurance coverage and emergency department use
Laurence C Baker1, Renee Y Hsia
1*Department of Health Research and Policy, Stanford University, Stanford, CA †Department of Emergency Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, CA.
Background:
Emergency departments (EDs) nationwide are key entry points into the health care system, and their use may reflect changes in access and need in their communities. However, no studies to date have empirically and longitudinally studied how changes in a community's level of insurance coverage, a key determinant of access, affect ED utilization.
Objective:
To determine the effects of changes in a community's rate of insurance coverage on its population's ED use.
Methods:
We conducted a longitudinal analysis of all California counties between 2005 and 2010 using comprehensive ED visit data from the California Office of Statewide Health Planning and Development. Using Poisson regression with county and year fixed effects, we determined how changes in the rate of insurance coverage within a given county affect ED visits per 1000 residents.
Results:
We found that changes in the rate of insurance coverage within a county had a slight but significant inverse relationship with ED visits per 1000 residents for both adults and children. For example, if a county's rate of insurance coverage among adults jumped from the 10th (73.22%) to the 90th percentile (84.93%), an estimated 2 fewer ED visits would occur per 1000 adult residents.
Conclusions:
As the rate of insurance coverage increased within California counties, overall ED utilization declined only slightly. Thus, expanding insurance coverage may not lead to significant decreases in overall ED use.
Related Concept Videos
01:30Methods of Documentation VII: EMR
01:30Specialized Care Centers and Settings-II
Rural health centers are specialized care facilities in remote locations with very few medical personnel. The primary care providers who run the centers are mostly Registered Nurse Practitioners. Here, emergency treatment is provided to critically ill or injured patients before they are transferred to the closest hospital. Fortunately, due to advancement in technology, many rural healthcare facilities and professionals have easy access to diagnostic and treatment...
01:22Standards of Care I
01:21Causality in Epidemiology
01:26Methods Of Healthcare Delivery System
Managed Care System:
The managed care system is designed to control the cost while maintaining the quality of care. The patient's care from admission to discharge is planned by the primary care provider or the case manager, also known as the gatekeeper. In a managed care system, the number of care providers is...
02:09Bystander Effect