• emergency service;
  • hospitals, teaching;
  • length of stay;
  • efficiency, organizational;
  • patient satisfaction;
  • faculty, medical.

Objectives: It is not clear how emergency medicine residents affect emergency department (ED) efficiency. The objective of this study was to determine whether a new emergency medicine residency program affected the length of stay (LOS) of patients in a community hospital ED. Methods: A before-and-after observational study was conducted during a one-year period prior to, and for three years after, the start of a new residency. An additional year's worth of data were collected during the fifth year after the residency started. Patients were excluded if their LOS was less than 30 minutes and they were admitted directly to the hospital. Explanatory variables included scheduled resident and student hours/day; scheduled faculty hours/day; nursing plus clerk hours/day; patients/day; ambulances/day; and admissions/day. The data were analyzed using descriptive and correlation statistics and regression analysis. Results: Average patient LOS prior to the residency was 122.9 minutes. During the first year of residency, it was 126.6 minutes; second year, 129.9 minutes; third year, 158.9 minutes; and fifth year, 162.4 minutes. There was a positive correlation between LOS and third-postgraduate-year resident (PGY-3) hours (rho = 0.43), and between LOS and PGY-3 hours/patients/day (rho = 0.42). All other correlations were poor (rho < 0.4). Conclusions: In this ED, there was a weak, positive correlation between ED patient length of stay and the presence of PGY-3 emergency medicine residents.