Table 4. Quality assessment by the AMSTAR 2 checklist.

Sl.No	AMSTAR 2 ITEMS	Dharmayani et al. [11]	Głąbska et al. [12]	Lassale et al. [16]	Quirk et al. [9]
		2021	2020	2018	2013
1.	Was an ‘a priori’ design provided?	No	Yes	No	No
2.	Was there duplicate study selection and data extraction?	Yes	Yes	Yes	Yes
3.	Was a comprehensive literature search performed?	Yes	Yes	Yes	Yes
4.	Was the status of publication (i.e. grey literature) used as an inclusion criterion?	Yes	Yes	Yes	Yes
5.	Was a list of studies (included and excluded) provided?	Yes	Yes	Yes	Yes
6.	Were the characteristics of the included studies provided?	Yes	Yes	Yes	Yes
7.	Was the scientific quality of the included studies assessed and documented?	Yes	Yes	Yes	Yes
8.	Was the scientific quality of the included studies used appropriately in formulating conclusions?	Yes	Yes	Yes	Yes
9.	Were the methods used to combine the findings of studies appropriate?	Yes	Yes	Yes	Yes
10.	Was the likelihood of publication bias assessed?	Yes	Yes	Yes	Yes
11.	Was the conflict of interest included?	Yes	No	Yes	Yes
	Total grade	HIGH	HIGH	HIGH	HIGH
	Total score out of 11	10	10	10	10
	Total percentage = 90.90%