Influence of covariates on heterogeneity in Hamilton Anxiety Scale ratings in placebo-controlled trials of benzodiazepines in generalized anxiety disorder: Systematic review and meta-analysis.

The major factors determining benzodiazepine response was baseline anxiety level for the benzodiazepine arm and study duration. In any design of further meta-analyses and clinical trials for generalized anxiety disorder we suggest that these should be considered these as confounding factors.