Association of emergency department boarding times on hospital length of stay for patients with psychiatric illness

Background Extended periods awaiting an inpatient bed in the emergency department (ED) may exacerbate the state of patients with acute psychiatric illness, increasing the time it takes to stabilise their acute problem in hospital. Therefore, we assessed the association between boarding time and hospital length of stay for psychiatric patients. Methods ED clinical records were linked to inpatient administrative records for all patients with a primary psychiatric diagnosis admitted to a Calgary, Alberta hospital between April 2014 and March 2018. The primary exposure was boarding time (admission decision to inpatient bed transfer), and primary outcome was inpatient length of stay. Confounders for this relationship, including indicators of illness severity, were selected a priori then the association was assessed using hierarchical Bayesian Poisson regression, which accounts for repeat observations of the same patient and differences between hospital sites. Changes in length of stay were measured using a rate ratio (ie, expected change in length of stay for each 1 hour increase in boarding time). Results A total of 19 212 admissions (14 261 unique patients) were included in the analysis. The average boarding time was 14 hours (range: 0-186 hours). Patients who were boarded for greater than 14 hours more frequently required a high-observation bed (14% vs 3.5%), received an antipsychotic (44% vs 14%) or received sedation (55% vs 33%) while in the ED. The probability that boarding time increased hospital length of stay (rate ratio: >1) was 92%, with a median increase for a patient boarded for 24 hours of 0.01 days. Conclusion Boarding in the ED was associated with a high probability of increasing the hospital length of stay for psychiatric patients; however, the absolute increase is minimal. Although slight, this signal for longer length of stay may be a sign of increased morbidity for psychiatric patients held in the ED.