title: The influence of procedure volumes and standardization of care on quality and efficiency in total joint replacement surgery.
abstract: BACKGROUND
  The relationship between surgeon and hospital procedure volumes and clinical outcomes in total joint arthroplasty has long fueled a debate over regionalization of care. At the same time, numerous policy initiatives are focusing on improving quality by incentivizing surgeons to adhere to evidence-based processes of care. The purpose of this study was to evaluate the independent contributions of surgeon procedure volume, hospital procedure volume, and standardization of care on short-term postoperative outcomes and resource utilization in lower-extremity total joint arthroplasty.
  
  
  METHODS
  An analysis of 182,146 consecutive patients who underwent primary total joint arthroplasty was performed with use of data entered into the Perspective database by 3421 physicians from 312 hospitals over a two-year period. Adherence to evidence-based processes of care was defined by administration of appropriate perioperative antibiotic prophylaxis, beta-blockade, and venous thromboembolism prophylaxis. Patient outcomes included mortality, length of hospital stay, discharge disposition, surgical complications, readmissions, and reoperations within the first thirty days after discharge. Hierarchical models were used to estimate the effects of hospital and surgeon procedure volume and process standardization on individual and combined surgical outcomes and length of stay.
  
  
  RESULTS
  After adjustment in multivariate models, higher surgeon volume was associated with lower risk of complications, lower rates of readmission and reoperation, shorter length of hospital stay, and higher likelihood of being discharged home. Higher hospital volume was associated with lower risk of mortality, lower risk of readmission, and higher likelihood of being discharged home. The impact of process standardization was substantial; maximizing adherence to evidence-based processes of care resulted in improved clinical outcomes and shorter length of hospital stay, independent of hospital or surgeon procedure volume.
  
  
  CONCLUSIONS
  Although surgeon and hospital procedure volumes are unquestionably correlated with patient outcomes in total joint arthroplasty, process standardization is also strongly associated with improved quality and efficiency of care. The exact relationship between individual processes of care and patient outcomes has not been established; however, our findings suggest that process standardization could help providers optimize quality and efficiency in total joint arthroplasty, independent of hospital or surgeon volume.
authors.affiliation: Department of Orthopaedic Surgery, Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, CA 94143-0728, USA. kevin.bozic@ucsf.edu
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Bozic
authors.forename: Judith
authors.initials: J
authors.lastname: Maselli
authors.forename: Penelope S
authors.initials: PS
authors.lastname: Pekow
authors.forename: Peter K
authors.initials: PK
authors.lastname: Lindenauer
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Vail
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Auerbach
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000592:standards* / Q000706:statistics & numerical data; D019645:Arthroplasty, Replacement, Knee / Q000592:standards* / Q000706:statistics & numerical data; D002983:Clinical Competence; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D005791:Patient Care / Q000592:standards / Q000639:trends; D011182:Postoperative Care / Q000592:standards / Q000639:trends; D011183:Postoperative Complications / Q000453:epidemiology; D011475:Prosthesis Failure; D011787:Quality of Health Care; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D016896:Treatment Outcome; D014481:United States; D016526:Workload