Date Available
5-9-2025
Year of Publication
2025
Document Type
Doctoral Dissertation
Degree Name
Doctor of Philosophy (PhD)
College
Public Health
Department/School/Program
Epidemiology and Biostatistics
Faculty
Dr. Richard Charnigo
Faculty
Dr. Erin Abner
Abstract
Three related analyses were performed to try to understand the immediate effects of Medicaid expansion on hospital systems in Kentucky. Medicaid expansion led to a large, sudden increase in the number of individuals eligible for various health care needs. This sudden increase in demand for health services lead to initial hypotheses regarding hospitals’ ability to handle this demand. The first analysis examined hospital average length of stay (LOS) using a linear mixed-effects model. Length of stay was modeled longitudinally between 2013 and 2015 to determine if significant changes in the slope of LOS could be detected after expansion (2014). Separate analyses were run using discharge data for births of newborns and all other discharges. In both analyses, no significant change could be detected. A follow-up analysis was performed to examine average LOS, median LOS, and 90th percentile LOS for hospitals using a group-based trajectory modeling (GBTM) approach. Separate GBTM models were created for the pre-expansion period and the post-expansion period to examine if structural changes were created. Between two and four groups were estimated for each measure, but few differences were generated between pre- and post-expansion models. Finally, an analysis predicting varying degrees of emergent use of the emergency department (ED) in the pre- and post-expansion periods using two different machine learning models was performed. The goal was to assess if 1) the ability to accurately predict non-emergent use changed after expansion, and 2) choice of predictive model impacts ability to predict non-emergent use. Choice of machine learning model did not impact predictive performance, and predictions were more accurate for the pre-expansion period compared to the post-expansion period. This was likely due to structural differences in inpatient and outpatient discharges between the two periods.
Digital Object Identifier (DOI)
https://doi.org/10.13023/etd.2025.147
Recommended Citation
Bushling, Cameron, "UNDERSTANDING THE IMPACT OF THE MEDICAID EXPANSION ON HOSPITAL LENGTH OF STAY AND EMERGENCY DEPARTMENT USE IN KENTUCKY" (2025). Theses and Dissertations--Epidemiology and Biostatistics. 47.
https://uknowledge.uky.edu/epb_etds/47
