FLEX November 2023

10970347, 2022, 10, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/hed.27121 by Mount Sinai Health System Icah, Wiley Online Library on [02/08/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

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positive rate in order to examine potential publication bias. 35

A single-arm meta-analysis was performed for SLN identification rate, SLNB positive rate, and RRR. Arcsine transformation of the data was carried out for the analy sis of overall proportions. 37 Inverse variance method (DerSimonian-Laird estimator) was used to estimate the between-study variance ( τ 2 ). 38 Results are presented as pooled estimates with 95% confidence intervals (CIs). A forest-plot graph was created for each outcome. Cochran's Q method was used to assess between stud ies heterogeneity. 39 I 2 was calculated as a measure of het erogeneity. 40 The I 2 value represents the percentage of total variation across studies caused by heterogeneity rather than by chance. According to the Cochrane criteria, values from 0% to 40% may signify low heteroge neity, 30% to 60% may represent moderate heterogeneity, 50% to 90% may represent substantial heterogeneity, and 75% to 100% represents considerable heterogeneity. Using a fixed effects model, we assumed that all studies came from a common population and that the effect size is not significantly different among the different trials. If the heterogeneity test produced a low probability value ( Q -statistic, p < 0.05), then a more conservative random effects model was used. Influence analysis 41 was

2.5 | Data synthesis and statistical analysis

Data from the included studies were summarized using descriptive statistics. Dichotomous variables were reported as counts and percentages, while continuous variables as median and 95% confidence interval (CI) calculated using the method described by McGrath et al. 36 Clinical mea sures were reported as provided by the individual studies. SLNB positive rate was defined as the proportion of SLN positivity in patients with cSCCHN, calculated as the number of patients with a positive SLN divided by the total number of patients with cSCCHN who under went a SLNB. SLN identification rate was defined as the number of patients with a lymph node identified at the histologic evaluation divided by the total number of patients with cSCCHN who underwent a SLNB. RRR was defined as the proportion of patients with a nodal recur rence after a negative SLNB.

FIGURE 1 PRISMA flow diagram [Color figure can be viewed at wileyonlinelibrary.com]