Table 2.

Newcastle-Ottawa scores of included studies (Note: A star system was used for allow a semi quantitative assessment of study quality. A study was awarded a maximum of four stars for the selection and three stars for exposure/outcome categories. A maximum of two stars were awarded for comparability).

Lead Author, Year	Selection	Comparability	Exposure/Outcome	Reference
Fucà, 2020	****	**	**	[32]
Corti, 2021	***	**	***	[38]
Fucà, 2021	****	**	***	[37]
Guven, 2021	****	**	***	[39]
Ligorio, 2021	***	**	***	[41]
Sahin, 2021	***	**	***	[36]
Zeng, 2021	****	**	***	[49]
Efil, 2021	No full-text data available			[40]
Sato, 2022	***	**	***	[44]
Gambichler, 2022	***	**	***	[43]
Susok, 2022	***	*	**	[42]
Chen, 2022	****	**	**	[45]
Baba, 2022	****	**	**	[46]
Lin, 2022	****	**	***	[47]
Perez-Martelo, 2022	****	**	***	[48]