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

Table 4 Results of ascertainment of the level of evidence using GRADE recommendations

Outcome	Exposure	Study numbers	GRADE					Evidence quality
Outcome	Exposure	Study numbers	Risk of bias	Inconsistency^*	Indirectness^**	Imprecision^***	Publication bias	Evidence quality
RA	Any type of vaccine	16	0	-1^a	0	0	0	Very Low
RA	HPV	7	0	-1^a	0	0	0	Very Low
RA	Influenza	5	0	0	0	0	0	Low
RA	COVID-19	3	0	-1^a	0	0	0	Very Low
RA	Anthrax	1	0	0	0	0	0	Very Low
RA	Herpes Zoster	1	0	0	0	0	0	Very Low
RA	Duration of follow-up<1year	3	0	-1^a	0	0	0	Very Low
RA	Duration of follow-up 鈮モ€�1 year	9	0	-1^a	0	0	0	Very Low
RA	Cohort study	12	0	-1^a	0	0	0	Very Low
RA	Cace-control study	4	0	-1^a	0	0	0	Very Low
RA	High quality study	9	0	-1^a	0	0	0	Very Low
RA	Moderate or Low quality study	7	0	-1^a	0	0	0	Very Low

RA: Rheumatoid Arthritis; Explanations: a. high heterogeneity; The relevant information on GRADE certainty of evidence can be found at
^* Inconsistency refers to the variability in the results across studies, often characterized by non-overlapping confidence intervals or high heterogeneity, suggesting that the studies are not measuring the same underlying effect. This could be due to differences in study populations, interventions, or methods. ^** Indirectness occurs when the population, intervention, or outcomes in the studies do not directly answer the review question, or the results are not directly applicable to the population or intervention of interest in the review. ^*** Imprecision refers to the lack of sufficient data to draw reliable conclusions, often due to wide confidence intervals or a small sample size in the studies, which prevent precise estimates of the effect

ISSN: 1471-2458