Drawing Contour-Enhanced Funnel Plot in R Software
Zhang Tian-songa · Journal of Evidence-Based Medicine · 2013
Objective To introduce how to draw a contour-enhanced funnel in R software and its application in meta-analysis.Methods It was illustrated on an example data to draw a contour-enhanced funnel by using funnel() function and trimfill() function in meta package in R software,and to perceive the missing studies in areas of statistical significance from the plot.Results The contour-enhanced funnel was asymmetry,and the studies seem to be missing in areas of non-significance,and it was explained that funnel plot asymmetry may be due to publication bias.Conclusions Contour-enhanced funnel could be used to help distinguish publication bias from other cause of funnel plot asymmetry.