title: An observational study to evaluate 2 target times for elective coronary bypass surgery.
abstract: BACKGROUND
  Guidelines for timing of elective bypass surgery were established by expert opinion; yet, there is little evidence to support the recommended target times.
  
  
  OBJECTIVE
  To estimate the effect of timing of the procedure on in-hospital mortality by comparing groups of patients that differ in the duration of time between decision to operate and performed procedure.
  
  
  METHODS
  We used a population-based registry to identify patients who underwent surgical coronary revascularization and their hospital discharge summaries to identify in-hospital death.
  
  
  METHODS
  We studied 9593 patients who underwent surgical revascularization between 1992 and 2006 after registration on a wait list for first-time isolated coronary artery bypass grafting on an elective basis.
  
  
  METHODS
  The outcome was postoperative in-hospital death. The study variable was the timing of surgery, categorized as short, prolonged, and excessive delays according to the guidelines.
  
  
  METHODS
  The probability of in-hospital death in relation to timing of surgery was modeled by logistic regression that included a precalculated risk score for in-hospital death, with weighting observations by inverse propensity scores for the 3 surgery timing groups.
  
  
  RESULTS
  In-hospital death among patients with short delays was one third as likely as among those with excessive delays: adjusted odds ratio=0.32 (95% confidence interval 0.20-0.51). The protective effect was smaller and not significant for patients with prolonged delays; odds ratio=0.78 (95% confidence interval, 0.38-1.63).
  
  
  CONCLUSIONS
  Our findings suggest a survival benefit from performing elective surgical revascularization within the time frame recommended by the stricter of the 2 guidelines. Our results have implications for health systems that provide universal coverage and that budget the annual number of procedures.
authors.affiliation: School of Population and Public Health, The University of British Columbia, Canada. boris.sobolev@ubc.ca
authors.forename: Boris G
authors.initials: BG
authors.lastname: Sobolev
authors.forename: Guy
authors.initials: G
authors.lastname: Fradet
authors.forename: Lisa
authors.initials: L
authors.lastname: Kuramoto
authors.forename: Basia
authors.initials: B
authors.lastname: Rogula
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001026:Coronary Artery Bypass / Q000401:mortality*; D017558:Elective Surgical Procedures / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors; D014850:Waiting Lists