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
Funnel plot 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 [13].
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.
