title: Spinal fusion in the United States: analysis of trends from 1998 to 2008.
abstract: METHODS
  Epidemiological study using national administrative data.
  
  
  OBJECTIVE
  To provide a complete analysis of national trends in spinal fusion from 1998 to 2008 and compare with trends in laminectomy, hip replacement, knee arthroplasty, percutaneous transluminal coronary angioplasty, and coronary artery bypass graft.
  
  
  BACKGROUND
  Previous studies have reported a rapid increase in volume of spinal fusions in the United States prior to 2001, but limited reports exist beyond this point, analyzing all spinal fusion procedures collectively.
  
  
  METHODS
  Data were obtained from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample for the years 1998 to 2008. Discharges were identified using International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes for the following procedures: spinal fusion, laminectomy, hip replacement, knee arthroplasty, percutaneous transluminal coronary angioplasty, and coronary artery bypass graft. Population-based utilization rates were calculated from the US census data.
  
  
  RESULTS
  Between 1998 and 2008, the annual number of spinal fusion discharges increased 2.4-fold (137%) from 174,223 to 413,171 (P < 0.001). In contrast, during the same time period, laminectomy, hip replacement, knee arthroplasty, and percutaneous coronary angioplasty yielded relative increases of only 11.3%, 49.1%, 126.8%, and 38.8% in discharges, while coronary artery bypass graft experienced a decrease of 40.1%. Between 1998 and 2008, mean age for spinal fusion increased from 48.8 to 54.2 years (P < 0.001), in-hospital mortality rate decreased from 0.29% to 0.25% (P < 0.01), and mean total hospital charges associated with spinal fusion increased 3.3-fold (P < 0.001). The national bill for spinal fusion increased 7.9-fold (P < 0.001).
  
  
  CONCLUSIONS
  Frequency, utilization, and hospital charges of spinal fusion have increased at a higher rate than other notable inpatient procedures, as seen in this study from 1998 to 2008. In addition, patient demographics and hospital characteristics changed significantly; in particular, whereas the average age for spinal fusion increased, the in-hospital mortality rate decreased.
authors.affiliation: Spine Research Foundation, Santa Monica, CA, USA. seanrajaee@gmail.com
authors.forename: Sean S
authors.initials: SS
authors.lastname: Rajaee
authors.forename: Hyun W
authors.initials: HW
authors.lastname: Bae
authors.forename: Linda E A
authors.initials: LE
authors.lastname: Kanim
authors.forename: Rick B
authors.initials: RB
authors.lastname: Delamarter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000706:statistics & numerical data / Q000639:trends; D019643:Arthroplasty, Replacement / Q000706:statistics & numerical data / Q000639:trends; D002648:Child; D002675:Child, Preschool; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data / Q000639:trends; D005260:Female; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007223:Infant; D007796:Laminectomy / Q000706:statistics & numerical data / Q000639:trends; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D013122:Spinal Diseases / Q000453:epidemiology / Q000601:surgery*; D013123:Spinal Fusion / Q000706:statistics & numerical data* / Q000639:trends*; D015996:Survival Rate; D014481:United States / Q000453:epidemiology; D055815:Young Adult