Emergency Department Psychiatric Boarding and Downstream Acute Care Utilization in Children

Emergency department (ED) length of stay (LOS) of children with acute psychiatric illness has become a national crisis. We evaluated the association of ED LOS and one-year ED revisits, repeat hospitalizations, and time to revisit among pediatric patients admitted for psychiatric care.

ED encounters from 2016-2024 at a tertiary urban children’s hospital were analyzed. Patients who lived within 35km of the ED and admitted to inpatient psychiatry on index visit were included and followed for one year. Primary outcomes included ED visits and hospitalizations for psychiatric illness within one year. Outcomes were modeled using zero-inflated negative binomial regression (ZINB), adjusting for markers of disease severity (inpatient LOS, inpatient medication classes), ED daily census and average emergency severity index (ESI), seasonality, COVID-era presentation, socioeconomic factors (Medicaid insurance, Child Opportunity Index [COI]), age, gender, and special populations (autism, suicide-related visits, substance use). A Cox proportional hazards regression assessed the secondary outcome of association between ED LOS and time to first revisit. Variance inflation factors confirmed model stability.

Among 2,568 eligible visits (excluding 87 transfers, 615 patients living >35km from the ED, and 1685 medical admissions), 64% were female, 62% black, 19% white, and 54% insured by Medicaid, 1.3% uninsured, and 36% with COI < 50th percentile. Median age was 14 (IQR 12 – 16), ED LOS was 9.4 hours (IQR 6.7h – 17.8h), and inpatient LOS 6.6 days (IQR 4.7d – 8.7d). ED index-visit LOS was not associated with ED revisits, hospitalizations, or time to revisit (all p > 0.2). Significant associations with revisits included Medicaid insurance (Incident Rate Ratio [IRR] 1.31), inpatient LOS (IRR 1.17/day), greater number of medication classes (IRR 1.15), female sex (IRR 1.15), COI < 25th percentile (IRR 1.10), and higher mean ED ESI (IRR 1.10/ level). On Cox analysis, only the interaction between ED LOS and substance use history was significant (hazard ratio of psychiatric readmission 1.19, p = 0.03).

ED LOS was not associated with downstream acute care utilization for most patients. Prolonged ED LOS was associated with earlier psychiatric readmission among patients with substance use, identifying a high-risk subgroup that may benefit from targeted interventions.