title: Drivers of surgery for the degenerative hip, knee, and spine: a systematic review.
abstract: BACKGROUND
  Surgical treatment for degenerative conditions of the hip, knee, and spine has an impact on overall healthcare spending. Surgical rates have increased dramatically and considerable regional variation has been observed. The reasons behind these increasing rates and variation across regions have not been well elucidated.
  
  
  OBJECTIVE
  We therefore identified demographic (D), social structure (SS), health belief (HB), personal (PR) and community resources (CR), and medical need (MN) factors that drive rates of hip, knee, and spine surgery.
  
  
  METHODS
  We conducted a systematic review to include all observational, population-based studies that compared surgical rates with potential drivers (D, SS, HB, PR, CR, MN). We searched PubMed combining key words focusing on (1) disease and procedure; (2) study methodology; and (3) explanatory models. Independent investigators selected potentially eligible studies from abstract review and abstracted methodological and outcome data. From an initial search of 256 articles, we found 37 to be potentially eligible (kappa 0.86) but only 28 met all our inclusion criteria.
  
  
  RESULTS
  Age, nonminority, insurance coverage, and surgeon enthusiasm all increased surgical rates. Rates of arthroplasty were higher for females with higher education, income, obesity, rurality, willingness to consider surgery, and prevalence of disease, whereas spinal rates increased with male gender, lower income, and the availability of advanced imaging.
  
  
  CONCLUSIONS
  Regional variation in these procedures exists because they are examples of preference-sensitive care. With strategies that may affect change in factors that are potentially modifiable by behavior or resources, extreme variation in rates may be reduced.
authors.affiliation: Department of Orthopaedic Surgery, University of California at Irvine, 101 The City Drive South, Pavilion III, Orange, CA 92868, USA. sbederma@uci.edu
authors.forename: S Samuel
authors.initials: SS
authors.lastname: Bederman
authors.forename: Charles D
authors.initials: CD
authors.lastname: Rosen
authors.forename: Nitin N
authors.initials: NN
authors.lastname: Bhatia
authors.forename: P Douglas
authors.initials: PD
authors.lastname: Kiester
authors.forename: Ranjan
authors.initials: R
authors.lastname: Gupta
mesh_terms: D000368:Aged; D019643:Arthroplasty, Replacement / Q000191:economics*; D005260:Female; D006301:Health Services Needs and Demand; D006621:Hip Joint / Q000601:surgery*; D006801:Humans; D007348:Insurance, Health; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D013131:Spine / Q000601:surgery*