Table 2.

MINORS for assessing the quality of included studies

Methodological item for nonrandomized studies	Elwan et al. [32]	Wang et al. [13]	Shiraki et al. [35]	Wang et al. [34]	Iwaski et al. [33]	Xin et al. [31]	Tian et al. [27]	Ho et al. [26]	Zhu et al. [36]
1. A clearly stated aim	2	2	2	2	2	2	2	2	2
2. Inclusion of consecutive patients	2	2	2	2	2	2	2	2	2
3. Prospective collection of data	2	0	0	0	0	0	0	0	0
4. Endpoints appropriate to the aim of the study	2	2	2	2	2	2	2	2	1
5. Unbiased assessment of the study endpoint	1	1	1	1	1	1	1	1	1
6. Follow-up period appropriate to the aim of the study	2	2	2	2	2	2	2	2	2
7. Loss to follow up less than 5%	2	2	2	2	2	2	2	2	2
8. Prospective calculation of the study size	0	0	0	0	0	0	0	0	0
9. An adequate control group	2	2	2	2	2	2	2	2	1
10. Contemporary groups	2	1	2	2	2	2	2	2	1
11. Baseline equivalence of groups	2	2	2	2	2	2	2	2	2
12. Adequate statistical analyses	2	2	1	2	2	2	2	2	1
13. MINORS score	20	18	18	19	19	19	19	19	15