TABLE 4.

Quality assessment of 18 included studies (see 14 questions in Appendix S2)

Criterion study	1	2	3	4	5	6	7	8	9	10	11	12	13	14	Total score
Chen (2016) 26	●	●	●	●	○	●	●	○	●	○	●	○	●	●	10
Lee (2012) 29	●	●	●	●	○	●	●	●	●	○	●	○	●	●	11
Leung (2011) 6	●	●	●	●	○	●	●	●	●	○	●	○	●	●	11
Powell (2009) 21	●	●	●	○	○	○	○	○	●	○	●	○	●	●	7
Shier (2016) 24	●	●	●	●	○	○	○	●	●	○	●	○	●	●	9
Sturm (2005) 15	●	●	●	●	○	●	●	○	●	○	●	○	●	●	10
Zhang (2016) 23	●	●	●	●	○	●	●	●	●	○	●	○	●	●	11
Auld (2009) 20	●	●	●	●	○	○	○	○	●	○	●	○	●	●	8
Davis (2009) 27	●	●	●	●	○	○	○	●	●	○	●	○	●	●	9
Fiechtner (2013) 28	●	●	●	●	○	○	○	●	●	○	●	○	●	●	9
Fiechtner (2015) 22	●	●	●	●	○	○	○	●	●	○	●	○	●	●	9
Galvez (2009) 18	●	●	●	●	●	●	●	●	●	○	●	○	●	●	12
Gorski Findling (2018) 19	●	●	●	●	○	○	○	○	●	○	●	○	●	●	8
Li (2015) 17	●	●	●	●	○	○	○	○	●	○	●	○	●	●	8
Mellor (2011) 16	●	●	●	●	○	○	○	●	●	○	●	○	●	●	9
Powell (2007) 13	●	●	●	○	○	○	○	○	●	○	●	○	●	●	7
Seliske (2009) 14	●	●	●	●	○	○	○	●	●	○	●	○	●	●	9
Wall (2012) 25	●	●	●	●	○	○	○	●	●	○	●	○	●	●	9

Note: ● denotes the answer ‘Yes’, and ○ denotes the answer ‘No’.