2011 1.90 [1.05, 3.42] Total (95% CI) 1.29 [0.86, 1.94] Total events Heterogeneity: [r.sup.2] = 0.18; [chi square] = 50.25, df = 4 (P < 0.00001); [I.sup.2] = 92% Test for overall effect: Z = 1.23 (P = 0.22) FIGURE 3: Forest plot and funnel plot
of overall colostomy rate.
The symmetry of the funnel plot
was further evaluated by Egger's linear regression test.7 Statistical analysis was undertaken using the program STATA 11.0 software (Stata Corporation, Texas).
The Funnel Plot
Indicates That the Results Were Not Asymmetrical.
A funnel plot
was used to examine publication bias.
The funnel plot
was applied to estimate the publication bias.
A funnel plot
was performed to assess for publication bias.
Publication bias of the included articles was assessed using Begg's funnel plot
. The results of funnel plot
showed that the shape of the funnel plot
seemed symmetrical (Figure 4) and did not show an obvious publication bias for rs2856718 or rs7453920 polymorphism.
Publication bias is usually evaluated visually with a funnel plot
, which is a simple scatter plot of the intervention effect estimates of individual studies against some measure of each study's size.
The existence of publication bias was initially checked by the graphical display of funnel plot
and then test by the Egger's.13,14
and Egger's linear regression tests were conducted to evaluate potential publication bias.
Publication bias was assessed visually using a funnel plot
and was tested formally by Egger's test, with p<0.10 indicating the presence of publication bias .
An interpretable funnel plot
should be based on at least 10 studies (Sterne et al., 2011), applying only to five of the results in Table 2.