title: Does Performance Vary Within the Same Hospital When Separately Examining Different Patient Subgroups?
abstract: Surgical quality programs, such as the American College of Surgeons NSQIP, provide reports based on specialty or procedure, with patients aggregated together. It is unknown whether hospital performance differs by patient subgroup (eg cancer vs noncancer patients), masking opportunities for improvement. Our objectives were to determine whether performance differs within a given hospital for 6 contrasting patient subgroups and to identify the percentage of hospitals with greater than chance differences in performance.
  
  
  
  Using the American College of Surgeons NSQIP data, adults undergoing lung resection, esophagectomy, hepatectomy, pancreatectomy, colectomy, and proctectomy (2005 through 2012) were divided into 6 contrasting subgroups (elderly vs nonelderly, white vs nonwhite, obese vs nonobese, renal insufficiency vs normal renal function, cancer vs noncancer, emergency vs nonemergency). The main end point was serious morbidity or mortality. Observed to expected ratios were constructed using hierarchical models and compared using paired t-tests (eg observed to expected for cancer cases compared with noncancer). Variation in performance differences was assessed using a randomization test and z-tests for proportions.
  
  
  
  From 433 hospitals, 221,518 patients were included. Overall quality differed for elderly vs nonelderly, renal insufficiency vs normal renal function patients, cancer vs noncancer, and emergency vs nonemergency (p < 0.05). Variation in within-hospital performance differences exceeded chance expectations for renal insufficiency vs normal renal function in 31.1% of hospitals, cancer vs noncancer in 40.8%, and emergency vs nonemergency patients in 55.4% (p < 0.001).
  
  
  
  Hospital performance within a given hospital varies by patient subgroup. Quality programs can consider separate reports for these subgroups to identify opportunities for quality improvement.
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL; Department of Surgery, University of Chicago Medical Center, Chicago, IL; Surgical Outcomes and Quality Improvement, Department of Surgery and Northwestern Institute for Comparative Effectiveness Research in Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL. Electronic address: jberian@facs.org.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Berian
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL; Department of Surgery, University of Chicago Medical Center, Chicago, IL.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Paruch
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Cohen
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL; Department of Surgery, University of Chicago Medical Center, Chicago, IL; Surgical Outcomes and Quality Improvement, Department of Surgery and Northwestern Institute for Comparative Effectiveness Research in Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Merkow
authors.affiliation: Surgical Outcomes and Quality Improvement, Department of Surgery and Northwestern Institute for Comparative Effectiveness Research in Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Allison R
authors.initials: AR
authors.lastname: Dahlke
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL; Department of Surgery, University of California Los Angeles, Los Angeles, CA; Department of Surgery, VA Greater Los Angeles Healthcare System, Los Angeles, CA.
authors.forename: Clifford Y
authors.initials: CY
authors.lastname: Ko
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL; Surgical Outcomes and Quality Improvement, Department of Surgery and Northwestern Institute for Comparative Effectiveness Research in Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Karl Y
authors.initials: KY
authors.lastname: Bilimoria
mesh_terms: D000367:Age Factors; D013505:Digestive System Surgical Procedures / Q000592:standards*; D004632:Emergency Medical Services / Q000592:standards*; D006761:Hospitals / Q000592:standards*; D006801:Humans; D009369:Neoplasms / Q000628:therapy; D017063:Outcome Assessment, Health Care; D011013:Pneumonectomy / Q000592:standards*; D058996:Quality Improvement; D051437:Renal Insufficiency / Q000628:therapy; D020379:Risk Adjustment