Safety of overlapping surgery at a high-volume referral center

Joseph A. Hyder, Kristine T. Hanson, Curtis B. Storlie, Amy Glasgow, Nageswar R. Madde, Michael J. Brown, Daryl J. Kor, Robert R. Cima, Elizabeth B. Habermann

Research output: Contribution to journalArticlepeer-review

49 Scopus citations


Objective: To compare safety profiles of overlapping and nonoverlapping surgical procedures at a large tertiary-referral center where overlapping surgery is performed. Background: Surgical procedures are frequently performed as overlapping, wherein one surgeon is responsible for 2 procedures occurring at the same time, but critical portions are not coincident. The safety of this practice has not been characterized. Methods: Primary analyses included elective, adult, inpatient surgical procedures from January 2013 to September 2015 available through University HealthSystem Consortium. Overlapping and nonoverlapping procedures were matched in an unbalanced manner (m:n) by procedure type. Confirmatory analyses from the American College of Surgeons-National Surgical Quality Improvement Program investigated elective surgical procedures from January 2011 to December 2014. We compared outcomes mortality and length of stay after adjustment for registry-predicted risk, case-mix, and surgeon using mixed models. Results: The University HealthSystem Consortium sample included 10,765 overlapping cases, of which 10,614 (98.6%) were matched to 16,111 nonoverlapping procedures. Adjusted odds ratio for inpatient mortality was greater for nonoverlapping procedures (adjusted odds ratio, OR = 2.14 vs overlapping procedures; 95% confidence interval, CI 1.23-3.73; P = 0.007) and length of stay was no different (+1% for nonoverlapping cases; 95% CI, -1% to +2%; P = 0.50). In confirmatory analyses, 93.7% (3712/3961) of overlapping procedures matched to 5,637 nonoverlapping procedures. The 30-day mortality (adjusted OR = 0.69 nonoverlapping vs overlapping procedures; 95% CI, 0.13-3.57; P = 0.65), morbidity (adjusted OR = 1.11; 95% CI, 0.92-1.35; P = 0.27) and length of stay (-4% for nonoverlapping; 95% CI, -4% to -3%; P < 0.001) were not clinically different. Conclusions: These findings from administrative and clinical registries support the safety of overlapping surgical procedures at this center but may not extrapolate to other centers.

Original languageEnglish (US)
Pages (from-to)639-644
Number of pages6
JournalAnnals of surgery
Issue number4
StatePublished - Apr 1 2017


  • American College of Surgeons
  • National Surgical Quality Improvement Program
  • University HealthSystem Consortium
  • concurrent surgery
  • length of stay
  • morbidity
  • mortality
  • overlapping surgery
  • patient experience
  • safety

ASJC Scopus subject areas

  • Surgery


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