title: The "July effect" in total shoulder arthroplasty.
abstract: BACKGROUND
  New medical doctors enter their residency fields in July, a time in the hospital in which patient morbidity and mortality rates are perceived to be higher. It remains controversial whether a "July effect" exists in different areas of medicine and surgery, including in orthopedic surgery. The purpose of this study is to test for the July effect in patients undergoing primary total shoulder arthroplasty (TSA).
  
  
  METHODS
  Patients who underwent primary TSA from 2005-2012 were identified using the American College of Surgeons National Surgical Quality Improvement Program database. Cases were categorized as involving residents or fellows and as occurring during the first academic quarter. Rates of composite and any adverse event outcomes were compared between patient groups using multivariate logistic regression.
  
  
  RESULTS
  A total of 1591 patients met the inclusion criteria. Of these cases, 711 (44.7%) had resident or fellow involvement and 390 (24.5%) were performed in the first academic quarter. There were few demographic and comorbidity differences between cases with and without residents or fellows or between cases performed during the first quarter and during the rest of the year. Overall, the rate of serious adverse events was 1.6% and the rate of any adverse events was 6.5%.
  
  
  CONCLUSIONS
  Using one of the largest cohorts of primary TSA patients, this study could not provide evidence for a July effect. In the context of the recent growth in the volume of TSA procedures, these findings provide important reassurance to patients that it is safe to schedule their elective procedures at training institutions during the first part of the academic year.
authors.affiliation: Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL, USA.
authors.forename: Allison J
authors.initials: AJ
authors.lastname: Rao
authors.affiliation: Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL, USA.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Bohl
authors.affiliation: Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL, USA.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Frank
authors.affiliation: Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL, USA.
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Cvetanovich
authors.affiliation: Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL, USA.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Nicholson
authors.affiliation: Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL, USA. Electronic address: Anthony.romeo@rushortho.com.
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Romeo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000072228:Arthroplasty, Replacement, Shoulder / Q000193:education*; D016208:Databases, Factual; D004503:Education, Medical, Graduate / Q000379:methods*; D005260:Female; D006801:Humans; D007396:Internship and Residency / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009985:Orthopedics / Q000193:education*; D011183:Postoperative Complications; D058996:Quality Improvement; D012189:Retrospective Studies; D055815:Young Adult
keywords: American College of Surgeons National Surgical Quality Improvement Program; July effect; Total shoulder arthroplasty; resident involvement; seasonal effect; surgical outcomes