Predictors of hospital admission after ED observation unit care

Abstract

Background: Emergency department observation units (EDOUs) represent an opportunity to efficiently manage patients with common conditions requiring short-term hospital care. Understanding which patients are ultimately admitted to the hospital after care in an EDOU may enhance patient selection for EDOU care.

Methods: We conducted a retrospective analysis of US emergency department visits resulting in admission to observation status using the National Hospital Ambulatory Care Survey (NHAMCS) from 2009 to 2010, a nationally representative sample. We used survey-weighted logistic regression to identify predictors at the patient level, visit level, and hospital level for inpatient hospital admission after EDOU care.

Results: Between 2009 and 2010, there were 4.65 million patient visits (95% confidence interval [CI], 3.68-5.63) to EDOUs in the United States. Of those evaluated in an EDOU, 40.4% (95% CI, 34.5%-46.6%) were admitted to the hospital after EDOU care. Progressively older patient age was a strong predictor of hospital admission: patients age older than 65 years were more than 5 times more likely to be admitted than patients age younger than 18 years (odds ratio, 5.36; 95% CI, 2.26-12.73). The only other visit-level factor associated with admission was a reason for visit of chest pain; this was associated with a lower rate of hospital admission (odds ratio, 0.61; 95% CI, 0.41-0.91).

Conclusion: Across the United States in 2009 to 2010, older patient age was a strong predictor of admission after EDOU care, suggesting that older patients are more likely to require inpatient hospital services after EDOU care than younger patients.