Association of nights and weekends and patterns of interfacility transfer and mortality for emergency general surgery patients.

Abstract

Background: Presentation during nights and weekends has been associated with variations in care and poor outcomes for many time-sensitive conditions such as trauma, stroke, and cardiac arrest. We sought to determine whether variation in clinical care and outcomes exists for patients treated by the emergency general surgery service at our trauma center.

Methods: We performed a retrospective cohort study at a Level 1 trauma center (2017-2022) of emergency general surgery patients who transferred from other facilities or presented directly to the emergency department. The primary exposure variable was presentation during nights and weekends versus weekdays. To test for changes in the volume of interfacility transfers, the primary outcome was transfer status. The secondary outcome was mortality. We performed risk adjustment using demographic data, payer status, and preexisting conditions. We conducted subgroup analyses for predominant diagnoses and sensitivity analyses by defining "off-hours" using alternative times.

Results: The study included 7,274 patients, including 5,303 (72.9%) who arrived during off-hours and 3,195 (43.9%) transfers. Mortality was 6.5% (n = 472 patients). Off-hour presentations were associated with a significantly greater risk-adjusted likelihood of presenting as a transfer (adjusted odds ratio, 2.11; 95% confidence interval, 1.87-2.40), a finding consistent across all subgroups except for patients with appendicitis, choledocholithiasis, or pancreatitis. Increases in age, interfacility transfer, decreases in initial systolic blood pressure, and increases in initial heart rate were all associated with a statistically significant increased risk of mortality. However, we found no difference in mortality based on timing of presentation (adjusted odds ratio, 0.80; confidence interval, 0.63-1.01). All findings were robust to sensitivity analyses.

Conclusion: Nights and weekends were associated with increased rates of interfacility transfer, although mortality was no greater than during weekdays. These findings have implications for staffing at both the referral and referring hospitals to optimize the timely treatment of patients with surgical emergencies.

Level of evidence: Care Management; Level III.