Hospital variation in risk-standardized hospital admission rates from US EDs among adults.

BACKGROUND: Variation in hospital admission rates of patients presenting to the emergency department (ED) may represent an opportunity to improve practice. We seek to describe national variation in hospital admission rates from the ED and to determine the degree to which variation is not explained by patient characteristics or hospital factors.

METHODS: We conducted a cross-sectional analysis of a nationally representative sample of ED visits among adults within the 2010 National Hospital Ambulatory Care Survey ED data of hospitals with admission rates from the ED between 5% and 50%. We calculated risk-standardized hospital admission rates (RSARs) from the ED using contemporary hospital profiling methodology, accounting for patients' sociodemographic and clinical characteristics.

RESULTS: Among 19831 adult ED visits in 252 hospitals, there were 4148 hospital admissions from the ED. After accounting for patients' sociodemographic and clinical factors, the median RSAR from the ED was 16.9% (interquartile range, 15.0%-20.4%), and 8.1% of the variation in RSARs was attributable to an institution-specific effect. Even after accounting for hospital teaching status, ownership, urban/rural location, and geographical location, 7.0% of the variation in RSARs from the ED was still attributable to an institution-specific effect.

CONCLUSIONS AND RELEVANCE: There was variation in hospital admission rates from the ED in the United States, even after adjusting for patients' sociodemographic and clinical characteristics and accounting for hospital factors. Our findings suggest that suggesting that the likelihood of being admitted from the ED is not only dependent on clinical factors but also at which hospital the patient seeks care.