title: Time to appendectomy and risk of perforation in acute appendicitis.
abstract: OBJECTIVE
  In the traditional model of acute appendicitis, time is the major driver of disease progression; luminal obstruction leads inexorably to perforation without timely intervention. This perceived association has long guided clinical behavior related to the timing of appendectomy.
  
  
  OBJECTIVE
  To evaluate whether there is an association between time and perforation after patients present to the hospital.
  
  
  METHODS
  Using data from the Washington State Surgical Care and Outcomes Assessment Program (SCOAP), we evaluated patterns of perforation among patients (≥18 years) who underwent appendectomy from January 1, 2010, to December 31, 2011. Patients were treated at 52 diverse hospitals including urban tertiary centers, a university hospital, small community and rural hospitals, and hospitals within multi-institutional organizations.
  
  
  METHODS
  The main outcome of interest was perforation as diagnosed on final pathology reports. The main predictor of interest was elapsed time as measured between presentation to the hospital and operating room (OR) start time. The relationship between in-hospital time and perforation was adjusted for potential confounding using multivariate logistic regression. Additional predictors of interest included sex, age, number of comorbid conditions, race and/or ethnicity, insurance status, and hospital characteristics such as community type and appendectomy volume.
  
  
  RESULTS
  A total of 9048 adults underwent appendectomy (15.8% perforated). Mean time from presentation to OR was the same (8.6 hours) for patients with perforated and nonperforated appendicitis. In multivariate analysis, increasing time to OR was not a predictor of perforation, either as a continuous variable (odds ratio =  1.0 [95% CI, 0.99-1.01]) or when considered as a categorical variable (patients ordered by elapsed time and divided into deciles). Factors associated with perforation were male sex, increasing age, 3 or more comorbid conditions, and lack of insurance.
  
  
  CONCLUSIONS
  There was no association between perforation and in-hospital time prior to surgery among adults treated with appendectomy. These findings may reflect selection of those at higher risk of perforation for earlier intervention or the effect of antibiotics begun at diagnosis but they are also consistent with the hypothesis that perforation is most often a prehospital occurrence and/or not strictly a time-dependent phenomenon. These findings may also guide decisions regarding personnel and resource allocation when considering timing of nonelective appendectomy.
authors.affiliation: Department of Surgery, University of Washington Medical Center, Seattle2University of Washington Surgical Outcomes Research Center, Seattle3Department of Global Health, University of Washington, Seattle.
authors.forename: Frederick Thurston
authors.initials: FT
authors.lastname: Drake
authors.affiliation: Department of Surgery, University of Washington Medical Center, Seattle2University of Washington Surgical Outcomes Research Center, Seattle.
authors.forename: Neli E
authors.initials: NE
authors.lastname: Mottey
authors.affiliation: University of Washington Surgical Outcomes Research Center, Seattle4Providence Regional Medical Center, Everett, Washington.
authors.forename: Ellen T
authors.initials: ET
authors.lastname: Farrokhi
authors.affiliation: Department of Surgery, Swedish Medical Center, Seattle, Washington.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Florence
authors.affiliation: Skagit Valley Hospital, Mt Vernon, Washington.
authors.forename: Morris G
authors.initials: MG
authors.lastname: Johnson
authors.affiliation: Department of Surgery, University of Washington Medical Center, Seattle3Department of Global Health, University of Washington, Seattle.
authors.forename: Charles
authors.initials: C
authors.lastname: Mock
authors.affiliation: Department of Surgery, Madigan Army Medical Center, Ft Lewis, Tacoma, Washington.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Steele
authors.affiliation: Department of Surgery, Virginia Mason Medical Center, Seattle, Washington.
authors.forename: Richard C
authors.initials: RC
authors.lastname: Thirlby
authors.affiliation: Department of Surgery, University of Washington Medical Center, Seattle2University of Washington Surgical Outcomes Research Center, Seattle.
authors.forename: David R
authors.initials: DR
authors.lastname: Flum
mesh_terms: D000328:Adult; D000367:Age Factors; D001062:Appendectomy; D001064:Appendicitis / Q000150:complications* / Q000175:diagnosis / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D006304:Health Status; D006801:Humans; D019458:Insurance Coverage; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D018579:Patient Selection; D012307:Risk Factors; D012421:Rupture / Q000209:etiology; D012737:Sex Factors; D061665:Time-to-Treatment; D014861:Washington; D055815:Young Adult