Table 2 Quality assessment of case–control studies according to Newcastle–Ottawa scale.
Study | Selection | Comparability | Exposure | Total |
|---|---|---|---|---|
Agrillo et al.30 | **** | ** | 6 | |
Badiee et al.12 | **** | ** | ** | 8 |
Bergin et al.32 | **** | ** | ** | 8 |
Chen et al.33 | **** | ** | ** | 8 |
Dube et al.34 | **** | ** | * | 7 |
Groff et al.37 | **** | * | * | 6 |
Huang et al.16 | **** | ** | ** | 8 |
Kang et al.38 | **** | ** | * | 7 |
Kimura et al.39 | **** | ** | * | 7 |
Klement et al.40 | **** | ** | ** | 8 |
Lee et al.41 | **** | ** | * | 7 |
Lee et al.42 | **** | ** | * | 7 |
Liang et al.43 | **** | ** | * | 7 |
Liu et al.44 | **** | ** | ** | 8 |
Nakashima et al.47 | **** | ** | * | 7 |
Pahys et al.14 | **** | ** | ** | 8 |
Plano et al.49 | **** | * | ** | 7 |
Reinard et al.2 | **** | ** | ** | 8 |
Ren et al.50 | **** | ** | ** | 8 |
Riederman et al.7 | **** | * | ** | 7 |
Sagi et al.52 | **** | * | ** | 7 |
Schnee et al.29 | **** | ** | 6 | |
Siemionow et al.7 | **** | ** | 6 | |
Wang et al.55 | **** | ** | 6 | |
Wang et al.3 | **** | ** | ** | 8 |
Woodroffe et al.4 | **** | ** | ** | 8 |
Zhang et al.15 | **** | ** | ** | 8 |