Funnel-plot of the effect size of size of randomized-controlled trials, non randomized-controlled trials and before-after studies

<p><b>Copyright information:</b></p><p>Taken from "Evidence based practice in postgraduate healthcare education: A systematic review"</p><p>http://www.biomedcentral.com/1472-6963/7/119</p><p>BMC Health Services Research 2007;7():119-119.</p><p>Published online 26 Jul 2007</p><p>PMCID:PMC1995214.</p><p>