title: Need for standardization of the measurement of preoperative weight in bariatric surgical patients in the UK: A survey of British Obesity and Metabolic Surgery Society (BOMSS) members.
abstract: BACKGROUND
  Weight loss is the most commonly used metric in comparing outcomes after bariatric surgery. This is frequently presented in the form of percentage of excess weight loss (%EWL). Patients' weight is measured at several time points prior to surgery. The time point selected as the preoperative weight can have significant effects upon the measurement of %EWL. This study aimed to investigate whether there was any standardization in the selection of preoperative weight amongst UK bariatric surgery healthcare professionals.
  
  
  METHODS
  A questionnaire survey was conducted among the delegates at the British Obesity and Metabolic Surgery Society (BOMSS) meeting in January 2011.
  
  
  RESULTS
  A total of 54 delegates (consultant & trainee surgeons, bariatric specialist nurses, dieticians and psychologists) responded to the survey. A wide variation was noted in which preoperative weight was used in the calculation of %EWL, both among various disciplines and also among the same disciplines. The majority (61%) used the preoperative weight recorded at the bariatric surgical assessment clinic prior to surgery. 20% of delegates used the highest recorded preoperative weight. The remainder of delegates used weight recorded on the day of surgery (17%) or the weight recorded during the first visit to a medical physician led weight management clinic (2%).
  
  
  CONCLUSIONS
  Variation in the measurement of the preoperative weight will lead to variations of calculated %EWL between different bariatric units or even between different disciplines in the same unit. This will make comparison of published outcome data difficult. This study highlights the urgent need for standardization.
authors.affiliation: Department of Bariatric Surgery, Royal Cornwall Hospital, UK. arun.ariyarathenam@nhs.net
authors.forename: A V
authors.initials: AV
authors.lastname: Ariyarathenam
authors.forename: D J
authors.initials: DJ
authors.lastname: Pournaras
authors.forename: J C
authors.initials: JC
authors.lastname: Tham
authors.forename: I
authors.initials: I
authors.lastname: Finlay
authors.forename: A
authors.initials: A
authors.lastname: Cota
mesh_terms: D000886:Anthropometry / Q000379:methods*; D050110:Bariatric Surgery / Q000592:standards*; D001835:Body Weight; D006801:Humans; D009765:Obesity / Q000601:surgery*; D013043:Specialties, Surgical / Q000592:standards; D011795:Surveys and Questionnaires; D015431:Weight Loss