Table 2.

The quality of the selected studies was assessed using the NOS.

	Studies	Selection	Comparability	Exposure	Total
2023	Cudna et al. (2023)	✫✫✫✫	✫	✫✫	7 stars
2023	Bronisz et al. (2023)	✫✫✫✫	✫✫	✫✫	8 stars
2020	Huang et al. (2020)	✫✫✫	✫✫	✫	6 stars
2020	El Moneam Abdallah et al. (2019)	✫✫✫	✫	✫	5 stars
2020	Tao et al. (2020)	✫✫✫	✫✫✫	✫	7 stars
2020	Li et al. (2020)	✫✫	✫✫	✫✫	6 stars
2019	Wang (2019)	✫✫	✫✫	✫	5 stars
2019	Zhang (2019)	✫✫	✫	✫✫	5 stars
2018	Meguid et al. (2018)	✫✫✫	✫✫	✫✫	7 stars
2018	Bronisz et al. (2018)	✫✫✫✫	✫✫	✫	7 stars
2017	Cudna et al. (2017)	✫✫✫	✫✫	✫	6 stars
2013	Zhang et al. (2013)	✫✫	✫	✫	4 stars
2009	Zhang and Hao (2009)	✫✫	✫	✫	4 stars