Increased Length of Emergency Department Boarding Is Not Associated with Increased Mortality

Objectives: Prior studies have shown an association between longer ED boarding time and higher inpatient mortality. Questioning the external validity of these findings, we hypothesized that length of ED boarding is not associated with increased mortality. Methods: This was a retrospective cohort study. The setting was an urban, academic ED with \u3e 100,000 annual patient volume. We included consecutive adult hospital admissions over a 5-month period (September 2016 to January 2017). Patients were excluded that were admitted to labor and delivery or hospice care. We defined boarding time as the time between when an admitting order was placed and when the clerk on the admitting floor documented the patient\u27s arrival. The primary outcome was inpatient mortality. Analysis consisted of multivariable logistic regression that tested the association between boarding time and a poor outcome. Boarding time of 0 - 2 hours was used as the reference. Covariates in the model included age, sex, the Charlson comorbidity index, shock index, ventilator requirement, and abnormal routine labs. Results: There were 9,666 admissions from the ED. The mean age was 58 years, 52% were female, and 68% African American. The median ED LOS was 470 (IQR 360 - 612] minutes and the median boarding time was 180 [IQR 126 - 262] minutes. Boarding was more than 6 hours in 12.8% of admissions and more than 12 hours in 1.6% of admissions. Inpatient mortality was 2.4%, and 30-day mortality was 3.9%. Inpatient mortality based on boarding time was 2.9% (0-2 hours), 2.4% (2-4 hours), 2.4% (4-6 hours), and 1.2% (\u3e6 hours). When adjusting for age, sex, comorbidities and physiological abnormalities, there was no signal of higher inpatient or 30-day mortality with prolonged boarding. The odd ratios for inpatient mortality for boarding times of 2-4 and 4-6 hours compared to 0-2 hours were 0.76 (95% CI 0.54-1.06) and 0.80 (95% CI 0.52-1.22). The OR for inpatient mortality for patients with boarding time \u3e 6 hours was 0.39 (95% CI 0.21-0.73). Conclusion: While boarding time is a driver of poor patient satisfaction, these results question the existing literature their association with poor outcomes. Furthermore, the reduced odds of death with prolonged boarding (\u3e 6 hours) suggests that unaccounted for admitting processes, which preferentially keep patients with lesser morbidity in the ED, may be present