title: Body mass index as a continuous predictor of outcomes after expander-implant breast reconstruction.
abstract: BACKGROUND
  Studies show that obesity is a risk factor for complications after expander/implant breast reconstructions. However, reports vary on the precise threshold of body mass index (BMI) as a predictor of heightened risk. We endeavored to link BMI as a continuous variable to overall complications in a single-surgeon series of expander-implant reconstructions.
  
  
  METHODS
  From 399 patients undergoing expander-implant reconstruction, 551 breasts were stratified to normal weight, overweight, and obese groups for analysis and comparison with previous studies. Logistic regression was performed to predict changes to risk profile per increment of BMI.
  
  
  RESULTS
  Complication rates for obese and overweight patients were significantly greater than for normal weight patients, that is, 21.1% and 24.0% versus 10.4%, respectively (P < 0.005). A unit increase in BMI predicted a 5.9% increase in the odds of a complication occurring, and 7.9% increase in the odds of reconstruction ending in failure.
  
  
  CONCLUSIONS
  By expanding the analysis of BMI to include patients who do not meet the traditional definition of obesity (BMI ≥ 30 kg/m), we demonstrated that simply overweight patients (25 ≤ BMI < 30 kg/m) had an elevated complication rate. Moreover, through regression analysis, we established that BMI as a continuous variable predicts outcomes from expander-based breast reconstruction.
authors.affiliation: From the *Division of Plastic and Reconstructive Surgery, Feinberg School of Medicine, Northwestern University; and †Northwestern Memorial Hospital, Chicago, IL.
authors.forename: Khang T
authors.initials: KT
authors.lastname: Nguyen
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Hanwright
authors.forename: John T
authors.initials: JT
authors.lastname: Smetona
authors.forename: Elliot M
authors.initials: EM
authors.lastname: Hirsch
authors.forename: Akhil K
authors.initials: AK
authors.lastname: Seth
authors.forename: John Y S
authors.initials: JY
authors.lastname: Kim
mesh_terms: D000328:Adult; D015992:Body Mass Index; D019928:Breast Implantation; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000601:surgery*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000453:epidemiology; D050177:Overweight / Q000453:epidemiology*; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D015626:Tissue Expansion; D016896:Treatment Outcome