Table 1.

Literature quality characteristics.

Author	The year of publication	Outcome index	Quality score
Wang and Xu [5]	2011	BCD	4
Li et al. [6]	2021	ACEF	5
Zhang and Lin [7]	2011	AC	3
Dai et al. [8]	2018	ACDEF	6
Zhang et al. [9]	2018	BCDEF	6
Wang [10]	2016	ADEF	5
Zeng et al. [11]	2021	BCDEF	6
Yan et al. [12]	2021	BC	3
Zhao et al. [13]	2019	B	2
Liu [14]	2020	CDEF	5