Primary Care and Emergency Room Visits: The Virginia All-Payer Claims Database

This study utilizes the Virginia all-payer claims database (APCD) to examine the relationship between primary care utilization and emergency department (ER) use and to explore geographic variation in primary care utilization and ER use. We hypothesize that higher rates of primary care utilization will be associated with lower ER use rates, with maps showing clear geographic patterns.

This retrospective observational analysis utilized Bayesian smoothing techniques, regression analysis, and geographic information system (GIS) mapping to explore the association of ER use with primary care utilization. Our analysis included 866 ZIP Code Tabulation Areas (ZCTAs) in Virginia.

Primary care utilization was significantly associated with ER usage rates. The results show that for every increase of 10 primary care visit rates per 1,000 population, ER use rates decline by 7 per 1,000. The maps show clusters of higher rates of PC utilization throughout central and eastern Virginia, with lower rates in many parts of southern Virginia. Higher rates of ER use are observed in western Virginia, particularly along the border with West Virginia, with clusters of lower rates in northern Virginia near Washington, DC.

Utilizing the Virginia APCD and GIS mapping, this study finds that primary care utilization is associated with lower rates of ER use. The maps show clear geographic patterns for both ER use and primary care utilization. Important next steps include identifying priority areas, exploring their characteristics, and conducting qualitative research to better understand local factors contributing to their high or low rates of ER use.