Table 1.

Quality assessment of included studies.

References	Year	Selection	Comparability	Exposure	Total
(Park et al., 2019)	2019	★★★	★	★★★	7
(Banerjee et al., 2019)	2019	★★★	★	★★★	7
(Ding et al., 2017)	2017	★★★★	★★	★★	8
(Riba-Llena et al., 2016)	2016	★★★	★★	★★	7
(Yao et al., 2014)	2014	★★★	★★	★★★	8
(Zhu et al., 2010)	2010	★★★	★★	★★★	8
(Liang and Chan, 2017)	2017	★★	★★	★★★	7