title: Cost-effectiveness of a low-carbohydrate diet and a standard diet in severe obesity.
abstract: OBJECTIVE
  Low-carbohydrate diets have become a popular alternative to standard diets for weight loss. Our aim was to compare the cost-effectiveness of these two diets.
  
  
  METHODS
  The patient population included 129 severely obese subjects (BMI = 42.9) from a randomized trial; participants had a high prevalence of diabetes or metabolic syndrome. We compared within-trial costs, quality-adjusted life years (QALYs), and the incremental cost-effectiveness ratio (CER) for the two study groups. We imputed missing values for QALYs. The CER was bootstrapped to derive 95% confidence intervals and to define acceptability cut-offs. We took a societal perspective for our analysis.
  
  
  RESULTS
  Total costs during the one year of the trial were 6742 dollars +/- 6675 and 6249 dollars +/- 5100 for the low-carbohydrate and standard groups, respectively (p = 0.78). Participants experienced 0.64 +/- 0.02 and 0.61 +/- 0.02 QALYs during the one year of the study, respectively (p = 0.17 for difference). The point estimate of the incremental CER was -1225 dollars/QALY (i.e., the low-carbohydrate diet dominated the standard diet). However, in the bootstrap analysis, the wide spread of CERs caused the 95% confidence interval to be undefined. The probabilities that the low-carbohydrate diet was acceptable, using cut-offs of 50,000 dollars/QALY, 100,000 dollars/QALY, and 150,000 dollars/QALY, were 72.4% 78.6%, and 79.8%, respectively.
  
  
  CONCLUSIONS
  The low-carbohydrate diet was not more cost-effective for weight loss than the standard diet in the patient population studied. Larger studies are needed to better assess the cost-effectiveness of dietary therapies for weight loss.
authors.affiliation: Division of General Internal Medicine, Department of Medicine, Weight and Eating Disorders Program, University of Pennsylvania, Philadelphia, PA 19104, USA. gildena@mail.med.upenn.edu
authors.forename: Adam Gilden
authors.initials: AG
authors.lastname: Tsai
authors.forename: Henry A
authors.initials: HA
authors.lastname: Glick
authors.forename: David
authors.initials: D
authors.lastname: Shera
authors.forename: Linda
authors.initials: L
authors.lastname: Stern
authors.forename: Frederick F
authors.initials: FF
authors.lastname: Samaha
mesh_terms: D000328:Adult; D003362:Cost-Benefit Analysis; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy*; D019057:Quality-Adjusted Life Years; D012720:Severity of Illness Index
chemical_list: D004040:Dietary Carbohydrates