title: Improved and more effective algorithms to screen for nutrient deficiencies after bariatric surgery.
abstract: Most bariatric guidelines recommend frequent lab monitoring of patients to detect nutrient and vitamin deficiencies as early as possible. The aim of this study was to optimize the cost effectiveness of the nutrient panel, by developing an algorithm, which detects nutrient deficiencies at lower costs.
  
  
  
  In this retrospective study, 2055 patients who had undergone Laparoscopic Roux-Y Gastric Bypass (LRYGB) and Laparoscopic Sleeve Gastrectomy (LSG) surgery at Catharina Hospital Eindhoven between January 2009 and December 2013 were included. Perioperative biochemical measurements (7 days before and 127 days after surgery) and measurements >549 days before surgery were excluded. For analysis, the most recent preoperative and postoperative measurements were selected for each biochemical parameter separately. First, the amount of moderate and severe deficiencies were calculated. Second, we investigated whether each variable (vitamins A, B1, B6, B12, D, folate, ferritin, zinc and magnesium) could predict the presence of deficiency.
  
  
  
  In total, 561 (LRYGB) and 831 (LSG) patients had at least preoperative and postoperative values of vitamin A, B1, B6, B12, D, folate, ferritin, zinc or magnesium. The algorithm reduces vitamin D, B12, B6, B1and ferritin examinations by 15, 11, 28, 28 and 38%, respectively, without missing clinically relevant deficiencies. The corresponding potential cost savings was 14%.
  
  
  
  This study identified substantial cost savings in laboratory test for both LRYGB and LSG procedures. The potential cost reduction of 14% might even be increased to 42% when less frequent moderate deficiencies are not screened anymore, whereas >99.0 of moderate deficiencies will be detected.
authors.affiliation: Department of Clinical Chemistry, Catharina Hospital Eindhoven, Eindhoven, The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: Bazuin
authors.affiliation: Department of Surgery, Catharina Hospital Eindhoven, Eindhoven, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Pouwels
authors.affiliation: Department of Eduction and Research, Catharina Hospital Eindhoven, Eindhoven, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Houterman
authors.affiliation: Department of Surgery, Catharina Hospital Eindhoven, Eindhoven, The Netherlands.
authors.forename: S W
authors.initials: SW
authors.lastname: Nienhuijs
authors.affiliation: Department of Surgery, Catharina Hospital Eindhoven, Eindhoven, The Netherlands.
authors.forename: J F
authors.initials: JF
authors.lastname: Smulders
authors.affiliation: Department of Clinical Chemistry, Catharina Hospital Eindhoven, Eindhoven, The Netherlands.
authors.forename: A K
authors.initials: AK
authors.lastname: Boer
mesh_terms: D000465:Algorithms; D050110:Bariatric Surgery / Q000009:adverse effects / Q000379:methods; D001774:Blood Chemical Analysis / Q000191:economics* / Q000379:methods; D003677:Deficiency Diseases / Q000175:diagnosis* / Q000191:economics / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000191:economics* / Q000379:methods; D008903:Minerals / Q000097:blood; D011183:Postoperative Complications; D012189:Retrospective Studies; D014815:Vitamins / Q000097:blood
chemical_list: D008903:Minerals; D014815:Vitamins