Rigorous control conditions diminish treatment effects in weight loss-randomized controlled trials.

ABSTRACT:

Background

It has not been established whether control conditions with large weight losses (WLs) diminish expected treatment effects in WL or prevention of weight gain (PWG)-randomized controlled trials (RCTs).

Subjects/methods

We performed a meta-analysis of 239 WL/PWG RCTs that include a control group and at least one treatment group. A maximum likelihood meta-analysis framework was used to model and understand the relationship between treatment effects and control group outcomes.

Results

Under the informed model, an increase in control group WL of 1 kg corresponds with an expected shrinkage of the treatment effect by 0.309 kg (95% confidence interval (-0.480, -0.138), P=0.00081); this result is robust against violations of the model assumptions.

Conclusions

SUBMITTER: Dawson JA 

PROVIDER: S-EPMC4826650 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature