Vaccination and rheumatoid arthritis: an updated systematic review and meta-analysis of data from 25,949,597 participants

Table 2 Risk of bias assessment in the 16 observational studies assessing the association between vaccinations and RA

Author	Selection^a	Comparability^b	Outcome	Quality score
Author	Selection^a	Comparability^b	ascertainment^c	(Total)
Verstraeten T 2008 [27]	鉁�鉁�鉁�	鉁�	鉁�鉁�	Medium (6)
Bengtsson C 2010 [31]	鉁�鉁�	鉁�鉁�	鉁�鉁�鉁�	High (7)
Ray P 2011 [23]	鉁�鉁�鉁�鉁�	鉁�鉁�	鉁�鉁�鉁�	High (9)
Chao C 2012 [30]	鉁�鉁�鉁�	鉁�	鉁�鉁�	Medium (6)
Ho TY 2012 [29]	鉁�鉁�鉁�鉁�	鉁�鉁�	鉁�鉁�	High (8)
Arnheim-Dahlstrom L 2013 [33]	鉁�鉁�鉁�鉁�	鉁�鉁�	鉁�鉁�	High (8)
Angelo MG 2014 [34]	鉁�鉁�鉁�	鉁�	鉁�鉁�	Medium (6)
Persson I 2014 [22]	鉁�鉁�鉁�鉁�	鉁�鉁�	鉁�鉁�鉁�	High (9)
Vaughn DW 2014 [28]	鉁�鉁�	鉁�	鉁�鉁�	Low (5)
Lai YC 2015 [21]	鉁�鉁�鉁�	0	鉁�鉁�	Low (5)
Bardenheier BH 2016 [32]	鉁�鉁�	鉁�鉁�	鉁�鉁�鉁�	High (7)
Geier DA 2016 [19]	鉁�鉁�鉁�	0	鉁�鉁�鉁�	Medium (6)
Geng Y 2023 [20]	鉁�鉁�鉁�鉁�	鉁�鉁�	鉁�鉁�鉁�	High (9)
Ju H J 2023 [25]	鉁�鉁�鉁�	鉁�鉁�	鉁�鉁�	High (7)
Yang G 2023 [26]	鉁�鉁�鉁�	鉁�鉁�	鉁�	Medium (6)
Jung SW 2024 [24]	鉁�鉁�鉁�	鉁�鉁�	鉁�鉁�鉁�	High (8)

We assessed the included case-control studies and cohort studies using the relevant items from the NOS scale (Available from: )
^a Selection refers to how participants are chosen for the study and whether the selection process is free from bias. ^b Comparability refers to the extent to which the groups being compared are similar at the baseline, controlling for potential confounding factors. ^c Outcome ascertainment refers to how the outcomes of interest are measured and whether the measurement process is consistent and reliable

ISSN: 1471-2458