Table 2. Quality assessment of the included studies using the Newcastle-Ottawa Scale.

Author	Selection	Comparability	Assessment	Overall
Badheka et al. [11]	3	2	2	Good
Chang et al. [12]	3	2	4	Good
Cheng et al. [13]	2	2	3	Good
Hsu et al. [14]	3	1	3	Good
Husein et al. [15]	3	2	4	Good
Lin et al. [16]	2	2	3	Good
Mayer et al. [17]	3	1	4	Good
Olesen et al. [18]	2	1	2	Fair
Shah et al. [19]	2	2	4	Good
Wang et al. [20]	3	2	2	Good
Wannamaker et al. [21]	3	2	3	Good
Wilson et al. [22]	3	2	3	Good