Table 2.

Quality assessment of studies using the Newcastle Ottawa scale

Study	Selection	Comparability	Outcome	Total score
Li 2016 [14]	☆☆☆	☆	☆☆	6
Liu 2016 [15]	☆☆☆☆	☆	☆☆☆	8
Kang 2018 [16]	☆☆☆	☆☆	☆☆	7
Mughal 2019 [17]	☆☆☆	☆	☆☆☆	7
Basgoz 2020 [18]	☆☆☆	☆☆	☆	6
Ebrahimpur 2020 [19]	☆☆☆☆	☆☆	☆☆☆	9
Rasu 2020 [20]	☆☆	☆	☆☆	5
Kumar 2021 [21]	☆☆	☆☆	☆☆	6
Lin 2021 [22]	☆☆☆	☆☆	☆☆☆	8
Jiang 2022 [23]	☆☆☆	☆☆	☆	6

High quality: ☆ ≥ 7; moderate quality: 4 ≤ ☆ ≤ 6; poor quality: ☆ ≤ 3