title: An estimation of the global volume of surgery: a modelling strategy based on available data.
abstract: BACKGROUND
  Little is known about the amount and availability of surgical care globally. We estimated the number of major operations undertaken worldwide, described their distribution, and assessed the importance of surgical care in global public-health policy.
  
  
  METHODS
  We gathered demographic, health, and economic data for 192 member states of WHO. Data for the rate of surgery were sought from several sources including governmental agencies, statistical and epidemiological organisations, published studies, and individuals involved in surgical policy initiatives. We also obtained per-head total expenditure on health from analyses done in 2004. Major surgery was defined as any intervention occurring in a hospital operating theatre involving the incision, excision, manipulation, or suturing of tissue, usually requiring regional or general anaesthesia or sedation. We created a model to estimate rates of major surgery for countries for which such data were unavailable, then used demographic information to calculate the total worldwide volume of surgery.
  
  
  RESULTS
  We obtained surgical data for 56 (29%) of 192 WHO member states. We estimated that 234.2 (95% CI 187.2-281.2) million major surgical procedures are undertaken every year worldwide. Countries spending US$100 or less per head on health care have an estimated mean rate of major surgery of 295 (SE 53) procedures per 100 000 population per year, whereas those spending more than $1000 have a mean rate of 11 110 (SE 1300; p<0.0001). Middle-expenditure ($401-1000) and high-expenditure (>$1000) countries, accounting for 30.2% of the world's population, provided 73.6% (172.3 million) of operations worldwide in 2004, whereas poor-expenditure (</=$100) countries account for 34.8% of the global population yet undertook only 3.5% (8.1 million) of all surgical procedures in 2004.
  
  
  CONCLUSIONS
  Worldwide volume of surgery is large. In view of the high death and complication rates of major surgical procedures, surgical safety should now be a substantial global public-health concern. The disproportionate scarcity of surgical access in low-income settings suggests a large unaddressed disease burden worldwide. Public-health efforts and surveillance in surgery should be established.
authors.affiliation: Department of Health Policy and Management, Harvard School of Public Health, Boston, MA, USA; Department of Surgery, University of California Davis, Sacramento, CA, USA. Electronic address: tweiser@hsph.harvard.edu.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Weiser
authors.affiliation: Department of Health Policy and Management, Harvard School of Public Health, Boston, MA, USA; Department of Surgery, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Scott E
authors.initials: SE
authors.lastname: Regenbogen
authors.affiliation: Department of Health Policy and Management, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Katherine D
authors.initials: KD
authors.lastname: Thompson
authors.affiliation: Department of Health Policy and Management, Harvard School of Public Health, Boston, MA, USA; Department of Surgery, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Alex B
authors.initials: AB
authors.lastname: Haynes
authors.affiliation: Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Stuart R
authors.initials: SR
authors.lastname: Lipsitz
authors.affiliation: Department of Health Policy and Management, Harvard School of Public Health, Boston, MA, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Berry
authors.affiliation: Department of Health Policy and Management, Harvard School of Public Health, Boston, MA, USA; Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Atul A
authors.initials: AA
authors.lastname: Gawande
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008017:Life Expectancy; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D013514:Surgical Procedures, Operative / Q000145:classification / Q000191:economics / Q000706:statistics & numerical data*; D014944:World Health Organization