title: The July Effect: is emergency department length of stay greater at the beginning of the hospital academic year?
abstract: BACKGROUND
  There has been concern of increased emergency department (ED) length of stay (LOS) during the months when new residents are orienting to their roles. This so-called "July Effect" has long been thought to increase LOS, and potentially contribute to hospital overcrowding and increased waiting time for patients. The objective of this study is to determine if the average ED LOS at the beginning of the hospital academic year differs for teaching hospitals with residents in the ED, when compared to other months of the year, and as compared to non-teaching hospitals without residents.
  
  
  METHODS
  We performed a retrospective analysis of a nationally representative sample of 283,621 ED visits from the National Hospital Ambulatory Medical Care Survey (NHAMCS), from 2001 to 2008. We stratified the sample by proportion of visits seen by a resident, and compared July to the rest of the year, July to June, and July and August to the remainder of the year. We compared LOS for teaching hospitals to non-teaching hospitals. We used bivariate statistics, and multivariable regression modeling to adjust for covariates.
  
  
  RESULTS
  Our findings show that at teaching hospitals with residents, there is no significant difference in mean LOS for the month of July (275 minutes) versus the rest of the year (259 min), July and August versus the rest of the year, or July versus June. Non-teaching hospital control samples yielded similar results with no significant difference in LOS for the same time periods. There was a significant difference found in mean LOS at teaching hospitals (260 minutes) as compared to non-teaching hospitals (185 minutes) throughout the year (p<0.0001).
  
  
  CONCLUSIONS
  Teaching hospitals with residents in the ED have slower throughput of patients, no matter what time of year. Thus, the "July Effect" does not appear to a factor in ED LOS. This has implications as overcrowding and patient boarding become more of a concern in our increasingly busy EDs. These results question the need for additional staffing early in the academic year. Teaching hospitals may already institute more robust staffing during this time, preventing any significant increase in LOS. Multiple factors contribute to long stays in the ED. While patients seen by residents stay longer in the ED, there is little variability throughout the academic year.
authors.affiliation: Highland Hospital, Alameda Health System, Oakland, California.
authors.forename: Christine
authors.initials: C
authors.lastname: Riguzzi
authors.affiliation: Highland Hospital, Alameda Health System, Oakland, California.
authors.forename: H Gene
authors.initials: HG
authors.lastname: Hern
authors.affiliation: Highland Hospital, Alameda Health System, Oakland, California.
authors.forename: Farnaz
authors.initials: F
authors.lastname: Vahidnia
authors.affiliation: Highland Hospital, Alameda Health System, Oakland, California.
authors.forename: Andrew
authors.initials: A
authors.lastname: Herring
authors.affiliation: Highland Hospital, Alameda Health System, Oakland, California.
authors.forename: Harrison
authors.initials: H
authors.lastname: Alter
mesh_terms: D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D019538:Health Care Surveys; D006784:Hospitals, Teaching / Q000706:statistics & numerical data; D006801:Humans; D007396:Internship and Residency / Q000706:statistics & numerical data*; D007902:Length of Stay / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013997:Time Factors; D014481:United States