Fig 3From: Serious adverse events reported in placebo randomised controlled trials of oral naltrexone: a systematic review and meta-analysisForest plot of the subgroup analysis by dose of the risk ratio (RR) of serious adverse events in RCTs of naltrexone vs placebo. Data in parentheses show the mean or range of participants’ age and the percentage of male or female participants. Double zero studies (i.e. those which reported zero events in each treatment group) were excluded from the meta-analysisBack to article page