Variation in hospital admission rates between a tertiary care and two freestanding emergency departments

Background: Recently, freestanding emergency departments (FSEDs) have grown significantly in number. Critics have expressed concern that FSEDs may increase healthcare costs.

Objective: We determined whether admission rates for identical diagnoses varied among the same group of physicians according to clinical setting.

Methods: This was a retrospective comparison of adult admission rates (n=3230) for chest pain, chronic obstructive pulmonary disease (COPD), asthma, and congestive heart failure (CHF) between a hospital-based ED (HBED) and two FSEDs throughout 2015. Frequency distribution and proportions were reported for categorical variables stratified by facility type. For categories with cell frequency less or equal to 5, Fisher's Exact test was used to calculate a P value. Chi square tests were used to assess difference in proportions of potential predictor variables between the HBED and FSEDs. For continuous variables, the mean was reported and Student's t-test assessed the difference in means between HBED and FSED patients. Multivariate logistic regression analyses were performed to estimate the unadjusted and adjusted prevalence odds ratio with 95% confidence interval (CI) for patient disposition outcomes associated with type of ED facility visited.

Results: Of 3230 patients, 53% used the HBED and 47% used the FSED. Patients visiting the HBED and FSED varied significantly in gender, acuity levels, diagnosis, and number of visits. Age was not significantly different between facilities. Multivariable adjusted estimated prevalence odds ratio for patients admitted were 1.2 [95%CI: 1.0-1.4] in the HBED facility compared to patients using FSEDs.

Conclusion: In our healthcare system, FSEDs showed a trend towards a 20% lower admission rate for chest pain, COPD, asthma and CHF.