xRead Articles - November 2022

intervention. The horizontal axis (x-axis) shows the contribution of each study to the overall Q-test statistic for heterogeneity. The standardized difference of the overall treatment effect is plotted on the vertical axis, showing the in fl uence of each study on the pooled effect size. Studies on top right have greater in fl uence on the results and have a bigger contribution to heterogeneity. 35 Analysis of publication bias was conducted for each treat ment group individually using the effect size of the subjective FS incidence. It was performed by visual inspection of the funnel plot, that is, a graphical representation of the size of trials plot ted against the effect size they report. It assumes small studies are more likely to be susceptible to publication bias than large ones. If publication bias does exist, it is most likely to be due to small negative trials not being published. As a consequence, an asymmetry in the scatter of small studies with more studies showing a positive result than those showing a negative result is evident at visual inspection in case of publication bias. Moreover,

the Egger ’ s regression intercept was measured to statistically examine the asymmetry of the funnel plot. 36 All the analyses were performed using the R software for statistical computing (R version 4.0.1; “ pcnetmeta ” and “ meta ” packages). Statistical signi fi cance was de fi ned as P < .05.

RESULTS Search Results and Studies Description

A fl ow chart of the study identi fi cation process is shown in Figure 1. The search strategy yielded 1,375 arti cles after duplicates were removed. After title and abstract review, 1,286 articles were rejected and full-texts of the remaining 101 papers were obtained and reviewed. After applying the abovementioned eligibility criteria, a

Fig. 1. PRISMA 2009 fl ow diagram. [Color fi gure can be viewed in the online issue, which is available at www.laryngoscope.com.]

Laryngoscope 131: August 2021

De Virgilio et al.: Surgical prevention of Frey syndrome 1763