title: Composite measures for profiling hospitals on bariatric surgery performance.
abstract: OBJECTIVE
  The optimal approach for profiling hospital performance with bariatric surgery is unclear.
  
  
  OBJECTIVE
  To develop a novel composite measure for profiling hospital performance with bariatric surgery.
  
  
  METHODS
  Using clinical registry data from the Michigan Bariatric Surgery Collaborative, we studied all patients undergoing bariatric surgery from January 1, 2008, through December 31, 2010. For laparoscopic gastric bypass surgery, we used empirical Bayes techniques to create a composite measure by combining several measures, including serious complications, reoperations, and readmissions; hospital and surgeon volume; and outcomes with other related procedures. Hospitals were ranked for 2008 through 2009 and placed in 1 of 3 groups: 3-star (top 20%), 2-star (middle 60%), and 1-star (bottom 20%). We assessed how well these ratings predicted outcomes in the next year (2010) compared with other widely used measures.
  
  
  METHODS
  Risk-adjusted serious complications.
  
  
  RESULTS
  Composite measures explained a larger proportion of hospital-level variation in serious complication rates with laparoscopic gastric bypass than other measures. For example, the composite measure explained 89% of the variation compared with only 28% for risk-adjusted complication rates alone. Composite measures also appeared better at predicting future performance compared with individual measures. When ranked on the composite measure, 1-star hospitals had 2-fold higher serious complication rates (4.6% vs 2.4%; odds ratio, 2.0; 95% CI, 1.1-3.5) compared with 3-star hospitals. Differences in serious complication rates between 1- and 3-star hospitals were much smaller when hospitals were ranked using serious complications (4.0% vs 2.7%; odds ratio, 1.6; 95% CI, 0.8-2.9) and hospital volume (3.3% vs 3.2%; odds ratio, 0.85; 95% CI, 0.4-1.7).
  
  
  CONCLUSIONS
  Composite measures are much better at explaining hospital-level variation in serious complications and predicting future performance than other approaches. In this preliminary study, it appears that such composite measures may be better than existing alternatives for profiling hospital performance with bariatric surgery.
authors.affiliation: The Michigan Bariatric Surgery Collaborative (MBSC), University of Michigan, Ann Arbor.
authors.forename: Justin B
authors.initials: JB
authors.lastname: Dimick
authors.affiliation: The Michigan Bariatric Surgery Collaborative (MBSC), University of Michigan, Ann Arbor.
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Birkmeyer
authors.affiliation: The Michigan Bariatric Surgery Collaborative (MBSC), University of Michigan, Ann Arbor.
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: Finks
authors.affiliation: Blue Cross Blue Shield of Michigan, Detroit.
authors.forename: David A
authors.initials: DA
authors.lastname: Share
authors.affiliation: Marquette General Hospital, Marquette, Michigan.
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: English
authors.affiliation: Henry Ford Health System, Detroit, Michigan.
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Carlin
authors.affiliation: The Michigan Bariatric Surgery Collaborative (MBSC), University of Michigan, Ann Arbor.
authors.forename: John D
authors.initials: JD
authors.lastname: Birkmeyer
mesh_terms: D050110:Bariatric Surgery / Q000592:standards*; D005260:Female; D015390:Gastric Bypass; D006761:Hospitals / Q000145:classification* / Q000592:standards*; D006801:Humans; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D011787:Quality of Health Care; D018570:Risk Assessment