title: Weight loss at first postoperative visit predicts long-term outcome of Roux-en-Y gastric bypass using Duke weight loss surgery chart.
abstract: BACKGROUND
  Roux-en-Y gastric bypass has been used for >3 decades. However, no normative data are available to aid the bariatric surgeon in assessing the adequacy of weight loss at each postoperative visit. The objective of the present study was to construct nomograms to aid in the assessment of weight loss. The setting was a university hospital in the United States.
  
  
  METHODS
  We used data prospectively collected from 1216 patients who had undergone Roux-en-Y gastric bypass at Duke University from April 2000 to September 2007. The percentage of excess weight loss (%EWL) was determined at each follow-up visit (1, 3, 6, 12, and 36 mo). The %EWL velocity was also determined using the postoperative data collected at the 1- and 3-month visits. Multivariate analysis was used to determine the predictive factors that influence the long-term results.
  
  
  RESULTS
  At 12 months of follow-up, most patients, especially those in the first and fourth quartiles (P = .01), continued to be in the same weight loss quartile they had initially been in at 1 month postoperatively. The positive and negative predictive value for the first quartile %EWL at 1 month resulting in a first quartile %EWL at 12 months was 39% and 81%, respectively. Multivariate analysis indicated that gender, preoperative body mass index, %EWL at 1 month, and %EWL velocity were statistically significant predictors of the %EWL at 12 months postoperatively.
  
  
  CONCLUSIONS
  We are the first group to determine that weight loss performance in the early period is a significant predictor of the long-term outcomes. The clinical utility of the weight loss chart is to identify underperformers early in the postoperative period to potentially improve their outcomes.
authors.affiliation: Department of Surgery, The Duke Center for Metabolic and Weight Loss Surgery, Duke University Medical Center, Durham, North Carolina 27704, USA.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mor
authors.forename: Lindsey
authors.initials: L
authors.lastname: Sharp
authors.forename: Dana
authors.initials: D
authors.lastname: Portenier
authors.forename: Ranjan
authors.initials: R
authors.lastname: Sudan
authors.forename: Alfonso
authors.initials: A
authors.lastname: Torquati
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D009767:Obesity, Morbid / Q000503:physiopathology / Q000601:surgery; D011182:Postoperative Care / Q000379:methods; D011446:Prospective Studies; D012016:Reference Values; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology*; D055815:Young Adult