Researchers at The Cleveland Clinic Heart Center performed a meta-analysis of seven large randomized trials of vitamin E (given alone or in combination with other antioxidants) and eight of beta carotene.
The meta-analysis reviewed the effect of these antioxidants on death from cardiovascular disease or from any other cause ("all-cause mortality").
"Efficacy of interventions for bronchiolitis in critically ill infants: a systematic review and meta-analysis."
A 2006 meta-analysis by the Child and Family Research Institute also shows that an epidural given too early can also double the C-section rate.
acyclovir therapy accelerates pain resolution in patients with herpes zoster: A meta-analysis of placebo-controlled trials.