B

Figure 2. Forest plot of HR for prediction of OS (A) and PFS (B) by PLR of laryngeal cancer patients.

3.3 Publication bias and Sensitivity analysis

Sensitivity analysis was used to assess the effect of each article on overall HR. As the result showed in figure 3 that deletion any article had no effect on the final OS. Published bias was evaluated by Begg’ s and Egger’ s test. We did not observe publication bias for OS, the result of publication bias was Pr>|z|=1.000 for Begg’s test and P>|t|=0.620 for Egger’s test. The publication bias of PFS was not carried out in the limited research.