Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2021 Sep 2;11(9):e049123. doi: 10.1136/bmjopen-2021-049123

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.

PMC Copyright notice

Funnel plot for analysis of publication bias. (A) Funnel plot established using Begg’s test for studies with overall survival (OS); (B) funnel plot using Egger’s test for studies with OS. (C) Funnel plot established utilising Begg’s test for studies with progression-free survival (PFS); (D) funnel plot using Egger’s test for studies with PFS.