title: Impact of gastrectomy procedural complexity on surgical outcomes and hospital comparisons.
abstract: BACKGROUND
  Most risk adjustment approaches adjust for patient comorbidities and the primary procedure. However, procedures done at the same time as the index case may increase operative risk and merit inclusion in adjustment models for fair hospital comparisons. Our objectives were to evaluate the impact of surgical complexity on postoperative outcomes and hospital comparisons in gastric cancer surgery.
  
  
  METHODS
  Patients who underwent gastric resection for cancer were identified from a large clinical dataset. Procedure complexity was characterized using secondary procedure CPT codes and work relative value units (RVUs). Regression models were developed to evaluate the association between complexity variables and outcomes. The impact of complexity adjustment on model performance and hospital comparisons was examined.
  
  
  RESULTS
  Among 3,467 patients who underwent gastrectomy for adenocarcinoma, 2,171 operations were distal and 1,296 total. A secondary procedure was reported for 33% of distal gastrectomies and 59% of total gastrectomies. Six of 10 secondary procedures were associated with adverse outcomes. For example, patients who underwent a synchronous bowel resection had a higher risk of mortality (odds ratio [OR], 2.14; 95% CI, 1.07-4.29) and reoperation (OR, 2.09; 95% CI, 1.26-3.47). Model performance was slightly better for nearly all outcomes with complexity adjustment (mortality c-statistics: standard model, 0.853; secondary procedure model, 0.858; RVU model, 0.855). Hospital ranking did not change substantially after complexity adjustment.
  
  
  CONCLUSIONS
  Surgical complexity variables are associated with adverse outcomes in gastrectomy, but complexity adjustment does not affect hospital rankings appreciably.
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL; Department of Surgery, Henry Ford Hospital, Detroit, MI.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Mohanty
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL; Department of Surgery, University of Chicago Pritzker School of Medicine, Chicago, IL.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Paruch
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL; Department of Surgery, Surgical Outcomes and Improvement Center, Feinberg School of Medicine, Northwestern University, Chicago, IL.
authors.forename: Karl Y
authors.initials: KY
authors.lastname: Bilimoria
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL.
authors.forename: Mark
authors.initials: M
authors.lastname: Cohen
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Vivian E
authors.initials: VE
authors.lastname: Strong
authors.affiliation: Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI. Electronic address: webers@surgery.wisc.edu.
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Weber
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D013505:Digestive System Surgical Procedures; D005260:Female; D005743:Gastrectomy / Q000401:mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality; D012086:Reoperation; D020379:Risk Adjustment / Q000379:methods*; D013274:Stomach Neoplasms / Q000601:surgery*; D014481:United States