Table 2.

Methodological quality scores based on MINORS and Downs and Black

First author [reference]	MINORS	0–10	Downs and Black	0–10	Mean
Meldrum et al. [21]	9	5.6	16	5	5.3
Chang et al. [22]	8	5	18	5.6	5.3
Ertel et al. [23]	10	6.3	23	7.2	6.8
Kopelman et al. [24]	6	3.8	9	2.8	3.3
Beck et al. [18]	9	5.6	17	5.3	5.5
Mcnelis et al. [25]	9	5.6	20	6.3	6.7
Mayberry et al. [26]	10	6.3	22	8.1	7.2
Balogh et al. [27]	12	7.5	20	6.3	6.9
Dolores-Velasquez et al. [28]	12	7.5	21	6.6	7.1
Zhou et al. [29]	10	6.3	15	4.7	5.5
Struck et al. [30]	8	5	19	5.9	5.5
Rollins et al. [31]	5	3.1	13	4.1	3.6
Divarci et al. [17]	10	6.3	17	5.3	5.8
De Waele et al. [32]	11	6.9	21	6.6	6.8
Peng et al. [33]	11	6.9	20	6.3	6.6

MINORS Methodological index for nonrandomized studies