TABLE 2.

Quality of the Included Cohort Studies

N.	Study	Selection				Comparability	Outcome			Total Of 9 scores
		1	2	3	4	II (**)	a	b	c		Class
1	Puntmann et al 15	*	*	*	‐	**	*	*	*	8	Good
2	Clark et al 28	*	*	*	‐	**	*	*	*	8	Good
3	Wang et al 10	*	*	*	‐	‐	*	*	*	6	Fair
4	Brito et al 29	*	*	*	‐	**	*	*	*	8	Good
5	Huang et al 24	‐	*	*	‐	‐	*	*	*	5	Fair
6	Eiros et al 26	*	*	*	‐	‐	*	*	*	6	Fair
7	Raman et al 13	*	*	*	‐	**	*	*	*	8	Good
8	Pan et al 16	*	*	*	‐	**	*	*	*	8	Good
9	Kotecha et al 21	*	*	*	‐	**	*	*	*	8	Good
10	Ng et al 17	‐	*	*	‐	‐	*	*	*	5	Fair
11	Vago et al 11	*	*	‐	‐	‐	*	*	*	5	Fair
12	Joy et al 23	*	*	*	‐	**	*	*	*	8	Good

1: Representativeness of exposed cohort (*).

2: Selection of nonexposed cohort (*).

3: Ascertainment of exposure (*).

4: The Outcome of Interest Was Not Present at Start of Study (*).

II: Comparability of Cohorts on the Basis of the Design or Analysis (**).

a: Assessment of outcome (*).

b: Enough follow‐up time for outcomes to occur (*).

c: Adequacy of follow‐up (*).