title: Size and distribution of the global volume of surgery in 2012.
abstract: OBJECTIVE
  To estimate global surgical volume in 2012 and compare it with estimates from 2004.
  
  
  METHODS
  For the 194 Member States of the World Health Organization, we searched PubMed for studies and contacted key informants for reports on surgical volumes between 2005 and 2012. We obtained data on population and total health expenditure per capita for 2012 and categorized Member States as very-low, low, middle and high expenditure. Data on caesarean delivery were obtained from validated statistical reports. For Member States without recorded surgical data, we estimated volumes by multiple imputation using data on total health expenditure. We estimated caesarean deliveries as a proportion of all surgery.
  
  
  RESULTS
  We identified 66 Member States reporting surgical data. We estimated that 312.9 million operations (95% confidence interval, CI: 266.2-359.5) took place in 2012, an increase from the 2004 estimate of 226.4 million operations. Only 6.3% (95% CI: 1.7-22.9) and 23.1% (95% CI: 14.8-36.7) of operations took place in very-low- and low-expenditure Member States representing 36.8% (2573 million people) and 34.2% (2393 million people) of the global population of 7001 million people, respectively. Caesarean deliveries comprised 29.6% (5.8/19.6 million operations; 95% CI: 9.7-91.7) of the total surgical volume in very-low-expenditure Member States, but only 2.7% (5.1/187.0 million operations; 95% CI: 2.2-3.4) in high-expenditure Member States.
  
  
  CONCLUSIONS
  Surgical volume is large and growing, with caesarean delivery comprising nearly a third of operations in most resource-poor settings. Nonetheless, there remains disparity in the provision of surgical services globally.
authors.affiliation: Stanford University Medical Center, Department of Surgery, 300 Pasteur Drive (S067), Stanford, CA 94305, United States of America (USA).
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Weiser
authors.affiliation: Ariadne Labs, Brigham and Women's Hospital and Harvard TH Chan School of Public Health, Boston, USA .
authors.forename: Alex B
authors.initials: AB
authors.lastname: Haynes
authors.affiliation: Ariadne Labs, Brigham and Women's Hospital and Harvard TH Chan School of Public Health, Boston, USA .
authors.forename: George
authors.initials: G
authors.lastname: Molina
authors.affiliation: Ariadne Labs, Brigham and Women's Hospital and Harvard TH Chan School of Public Health, Boston, USA .
authors.forename: Stuart R
authors.initials: SR
authors.lastname: Lipsitz
authors.affiliation: Stanford University Medical Center, Department of Surgery, 300 Pasteur Drive (S067), Stanford, CA 94305, United States of America (USA).
authors.forename: Micaela M
authors.initials: MM
authors.lastname: Esquivel
authors.affiliation: Stanford University Medical Center, Department of Surgery, 300 Pasteur Drive (S067), Stanford, CA 94305, United States of America (USA).
authors.forename: Tarsicio
authors.initials: T
authors.lastname: Uribe-Leitz
authors.affiliation: Stanford University Management Science and Engineering, Stanford, USA .
authors.forename: Rui
authors.initials: R
authors.lastname: Fu
authors.affiliation: Stanford University School of Medicine, Stanford, USA .
authors.forename: Tej
authors.initials: T
authors.lastname: Azad
authors.affiliation: Department of Surgery, Massachusetts General Hospital, Boston, USA .
authors.forename: Tiffany E
authors.initials: TE
authors.lastname: Chao
authors.affiliation: Ariadne Labs, Brigham and Women's Hospital and Harvard TH Chan School of Public Health, Boston, USA .
authors.forename: William R
authors.initials: WR
authors.lastname: Berry
authors.affiliation: Ariadne Labs, Brigham and Women's Hospital and Harvard TH Chan School of Public Health, Boston, USA .
authors.forename: Atul A
authors.initials: AA
authors.lastname: Gawande
mesh_terms: D016208:Databases, Factual; D005260:Female; D013502:General Surgery / Q000706:statistics & numerical data; D014943:Global Health; D005102:Health Expenditures / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D013514:Surgical Procedures, Operative / Q000191:economics* / Q000706:statistics & numerical data*