title: Time of day is associated with postoperative morbidity: an analysis of the national surgical quality improvement program data.
abstract: OBJECTIVE
  To examine the association between surgical start time and morbidity and mortality for nonemergent procedures.
  
  
  BACKGROUND
  Patients require medical services 24 hours a day. Several studies have demonstrated a difference in outcomes over the course of the day for anesthetic adverse events, death in the ICU, and dialysis care. The relationship between operation start time and patient outcomes is yet undefined.
  
  
  METHODS
  We performed a retrospective cohort study of 144,740 nonemergent general and vascular surgical procedures performed within the VA Medical System 2000-2004 and entered into the National Surgical Quality Improvement Program Database. Operation start time was the independent variable of interest. Logistic regression was used to adjust for patient and procedural characteristics and to determine the association between start time and, in 2 independent models, mortality and morbidity.
  
  
  RESULTS
  Unadjusted later start time was significantly associated with higher surgical morbidity and mortality. After adjustment for patient and procedure characteristics, mortality was not significantly associated with start time. However, after appropriate adjustment, operations starting between 4 pm and 6 pm were associated with an elevated risk of morbidity (OR = 1.25, P < or = 0.005) over those starting between 7 am and 4 pm as were operations starting between 6 pm and 11 pm (OR = 1.60, P < or = 0.005).
  
  
  CONCLUSIONS
  When considering a nonemergent procedure, surgeons must bear in mind that cases that start after routine "business" hours within the VA System may face an elevated risk of complications that warrants further evaluation.
authors: Department of Surgery, Philadelphia VA Medical Center, Philadelphia, PA, USA. rapaporr@uphs.upenn.edu
authors: Rachel R
authors: RR
authors: Kelz
authors: Kathryn M
authors: KM
authors: Freeman
authors: Patrick W
authors: PW
authors: Hosokawa
authors: David A
authors: DA
authors: Asch
authors: Francis R
authors: FR
authors: Spitz
authors: Miriam
authors: M
authors: Moskowitz
authors: William G
authors: WG
authors: Henderson
authors: Marc E
authors: ME
authors: Mitchell
authors: Kamal M F
authors: KM
authors: Itani
mesh_terms: D015331:Cohort Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012189:Retrospective Studies; D013514:Surgical Procedures, Operative / Q000009:adverse effects* / Q000401:mortality*; D013995:Time