Table 4.

Assessment of the quality of included observational studies^a

	Selection	Comparability	Outcome	Total
Lee et al. [44]	4	0	2	6
Kreissl et al. [43]	4	0	3	7
Kim et al. [42]	4	2	3	9
Colaizy et al. [39]	4	2	3	9
Chowning et al. [38]	4	2	3	9
Hair et al. [41]	4	0	3	7
Madore et al. [45]	4	2	3	9
Ginovart et al. [40]	4	0	3	7

^a Numbers represent the total number of stars obtained by the observational study in each quality domain