title: Predicting postoperative complications after bariatric surgery: the Bariatric Surgery Index for Complications, BASIC.
abstract: Around 20% of bariatric surgery patients develop a short- or long-term complication.
  
  
  
  Aim of this study was to develop a risk model predicting complications: the Bariatric Surgery Index for Complications (BASIC).
  
  
  
  The Obesity Center Amsterdam, located in a large teaching hospital, in Amsterdam, The Netherlands.
  
  
  
  A prospective consecutive database including patients operated between November 2007 and February 2015 was used. For the BASIC, analysis according to the TRIPOD statement was performed to identify risk factors for complications. Class I included patients with zero to one risk factor, class II patients with two risk factors, and class III patients with three or more risk factors.
  
  
  
  Of 1709 analyzed patients, mean age was 45 years (±SD 10.7), 1393 (81.5%) were female; mean body mass index was 44.5 kg/m2(6.8). Overall, 271 (15.9%) patients developed a complication of which 197 (72.5%) occurred within 30 days. Predictors in multivariable analysis were use of anticoagulants (odd's ratio (OR) 1.5); chronic obstructive pulmonary disease (OR 2.3); dyslipidemia (OR 1.4); gender (OR 1.4); psychiatric history (OR 1.3); and revisional surgery (OR 1.5). In class I, 13.5% (181 out of 1338) experienced complications, in class II 58 (21.6%) of the 269 patients and in class III 32 (31.4%) of the 102 patients, respectively. There was a significant difference (p < 0.001) in both overall and 30 day complications.
  
  
  
  The BASIC uses six preoperative variables to classify patients in a low-, intermediate-, or high-risk group for postoperative complications after bariatric surgery.
authors.affiliation: Departments of Surgery, Onze Lieve Vrouwe Gasthuis, locatie West (Prevoiusly Sint Lucas Andreas Ziekenhuis, Amsterdam), Jan Tooropstraat 161, 1064 AE, Amsterdam, The Netherlands. usha.coblijn@gmail.com.
authors.forename: Usha K
authors.initials: UK
authors.lastname: Coblijn
authors.affiliation: Departments of Surgery, Tergooi Ziekenhuizen, Blaricum, The Netherlands.
authors.forename: Julian
authors.initials: J
authors.lastname: Karres
authors.affiliation: Departments of Surgery, Onze Lieve Vrouwe Gasthuis, locatie West (Prevoiusly Sint Lucas Andreas Ziekenhuis, Amsterdam), Jan Tooropstraat 161, 1064 AE, Amsterdam, The Netherlands.
authors.forename: Christel A L
authors.initials: CAL
authors.lastname: de Raaff
authors.affiliation: Departments of Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.
authors.forename: Steve M M
authors.initials: SMM
authors.lastname: de Castro
authors.affiliation: Departments of Surgery, Erasmus Medisch Centrum, Rotterdam, The Netherlands.
authors.forename: Sjoerd M
authors.initials: SM
authors.lastname: Lagarde
authors.affiliation: Departments of Surgery, Onze Lieve Vrouwe Gasthuis, locatie West (Prevoiusly Sint Lucas Andreas Ziekenhuis, Amsterdam), Jan Tooropstraat 161, 1064 AE, Amsterdam, The Netherlands.
authors.forename: Willem F
authors.initials: WF
authors.lastname: van Tets
authors.affiliation: Departments of Surgery, Vrije Universiteit Medisch Centrum, Amsterdam, The Netherlands.
authors.forename: H Jaap
authors.initials: HJ
authors.lastname: Bonjer
authors.affiliation: Departments of Surgery, Onze Lieve Vrouwe Gasthuis, locatie West (Prevoiusly Sint Lucas Andreas Ziekenhuis, Amsterdam), Jan Tooropstraat 161, 1064 AE, Amsterdam, The Netherlands.
authors.forename: Bart A
authors.initials: BA
authors.lastname: van Wagensveld
mesh_terms: D000328:Adult; D050110:Bariatric Surgery / Q000009:adverse effects*; D015992:Body Mass Index; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D009767:Obesity, Morbid / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors
keywords: Bariatric surgery; Complications; Prediction model; Roux-en-Y gastric bypass; Sleeve gastrectomy