Table 2.

Quality Assessment: Cohort study quality according to the Newcastle Ottawa scale.

Study	Selection∗∗∗∗∗∗				Comparability∗∗	Outcome∗∗∗∗∗			Total Quality Score
	1	2	3	4	5	6	7	8
Family cluster
Chan et al., 20208	∗	0	∗	0	∗	∗	0	0	4
Ye et al., 202012	∗	0	∗	0	0	∗	0	0	3
Bai et al., 20207	∗	0	∗	0	0	∗	0	0	3
Xie et al., 202156	∗	0	∗	0	0	∗	0	0	3
Zhang et al., 202157	∗	0	∗	0	0	∗	0	0	3
Adults
Tian et al., 202021	∗	0	∗	0	0	∗	0	0	3
Kong et al., 20208	∗	0	∗	0	0	∗	0	0	3
Yin et al., 202022	∗	0	∗	0	0	∗	0	0	3
Meng et al., 202055	∗	0	∗	0	0	∗	0	0	3
Al Hosani et al., 201915	∗	0	∗	0	0	∗	0	0	3
He et al., 202016	∗	0	∗	0	0	∗	0	0	3
Qiu et al., 202020	∗	0	∗	0	0	∗	0	0	3
De laval et al., 202161	∗	0	∗	0	0	∗	0	0	3
Wong et al., 202034	∗	0	∗	0	∗	∗	0	0	4
Huang et al., 202060	∗	0	∗	0	0	∗	0	0	3
Sugano et al., 202058	∗	0	∗	0	0	∗	0	0	3
Nsekye et al., 202162	∗	0	∗	0	0	∗	0	0	3
Children
Hu et al., 202025	∗	0	∗	0	0	∗	0	0	3
Qiu et al., 201926	∗	0	∗	0	0	∗	0	0	3
Tan et al., 20201	∗	0	∗	0	0	∗	0	0	3
Sun et al., 202059	∗	0	∗	0	0	∗	0	0	3
Health care Workers
Schoierzeck et al., 202029	∗	0	∗	0	0	∗	0	0	3
Lucar et al., 202028	∗	0	∗	0	0	∗	0	0	3

Note: Selection; 1) Representativeness of the exposed cohort, 2) Selection of the non-exposed cohort, 3) Ascertain exposure, 4) Demonstration that outcome of interest was not present at the start of the study; Comparability; 5) Comparability of cohorts based on the design or analysis controlled for confounders; Outcome: 6) Assessment of outcome, 7) Was follow-up long enough for outcomes to occur, 8) Adequacy of follow-up of cohorts.

∗Newcastle-Ottawa Scale contains 8 items within 3 domain and the total maximum score is 9. A study with score from 7-9, has high quality, 4-6, high risk, and 0-3 very high risk of bias.