Cost-effectiveness of a low-carbohydrate diet and a standard diet in severe obesity.
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.
Tsai
Adam Gilden
AG
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
Glick
Henry A
HA
Shera
David
D
Stern
Linda
L
Samaha
Frederick F
FF
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
D004040:Dietary Carbohydrates