title: National trends in bariatric surgery, 1996-2002.
abstract: BACKGROUND
  Surgical therapy for the long-term treatment of obesity ("bariatric surgery") in individuals whose body mass index (calculated as weight in kilograms divided by the square of height in meters) is 40 or higher or in those who have significant obesity-related comorbidities and a body mass index of 35 or higher is one of few interventions shown to be effective. Many aspects of recent national bariatric surgery trends are unclear, including the ages of individuals undergoing such procedures and the economic burden borne by public vs private payers.
  
  
  OBJECTIVE
  Population-adjusted rates of bariatric surgery are rapidly increasing and have economic implications that differ for private vs public payers.
  
  
  METHODS
  We examined hospitalization and charge data from the Nationwide Inpatient Sample from 1996 through 2002, representative of national patterns for children and adults. We derived nationally weighted estimates of population-adjusted hospitalization rates and inflation-adjusted charges for bariatric surgery. We also examined the relative economic burden for public vs private payers for bariatric surgery discharges.
  
  
  RESULTS
  Population-adjusted rates of bariatric surgery in the overall sample increased more than 7-fold in the study period, from 3.5 per 100 000 US population in 1996 to 24.0 per 100 000 in 2002. During this period, among youth (<20 years old), rates increased from 0.23 per 100 000 to 0.73 per 100 000; and among elderly persons (>65 years old), rates increased from 0.30 per 100 000 to 1.69 per 100 000. The rate increased most dramatically among those aged 20 to 65 years, who composed 97% or more of bariatric surgery discharges annually. Increases in bariatric surgical volume corresponded with increasing economic consequences overall, exceeding USD $2 billion in annual charges by 2002 (mean, USD $29,107 per discharge). Since 2000, private payers have been charged for more than 80% of the national total; annual charges to Medicare and Medicaid have been comparatively modest, but each exceeded USD $100 million by 2002.
  
  
  CONCLUSIONS
  National rates of bariatric surgery have increased markedly among children and adults, with attendant economic consequences, principally for private insurers. This trend may reflect the dearth of effective primary care and preventive interventions to address the obesity epidemic.
authors.affiliation: Department of Pediatrics, University of Michigan, 300 N. Ingalls, Rm. 6C23, Ann Arbor, MI 48109-0456, USA. mattdav@med.umich.edu
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Davis
authors.forename: Kathryn
authors.initials: K
authors.lastname: Slish
authors.forename: Celia
authors.initials: C
authors.lastname: Chao
authors.forename: Michael D
authors.initials: MD
authors.lastname: Cabana
mesh_terms: D000328:Adult; D000368:Aged; D050110:Bariatric Surgery / Q000191:economics / Q000706:statistics & numerical data / Q000639:trends*; D005260:Female; D017722:Hospital Charges; D006801:Humans; D019458:Insurance Coverage; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications / Q000601:surgery; D014481:United States