Funnel plots of studies included in meta-analysis on the effect of garlic on systolic blood pressure (A) and diastolic blood pressure (B). The vertical line of Begg's funnel plot represents the pooled mean effect size, the dotted lines the 95% confidence interval, p-values are derived from Egger's test. Abbreviations: SB, systolic blood pressure; DBP, diastolic blood pressure; SE, standard error; mm Hg, millimetre mercury.
Ried et al. BMC Cardiovascular Disorders 2008 8:13 doi:10.1186/1471-2261-8-13