Table 2 Newcastle-Ottawa quality assessment of the included studies
Study | Selection | Comparability | Outcome | Scores | |||||
|---|---|---|---|---|---|---|---|---|---|
Representativeness of the exposed cohort | Selection of the non-exposed cohort | Ascertainment of exposure | Outcome of interest was presented | Assessment of outcome | Follow-up long enough for outcomes to occur | Adequacy of follow-up of cohorts | |||
Kawakami et al. [10] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Hwang et al. [19] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Murakami et al. [11] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Hirano et al. [12] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Komaya et al. [13] | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 8 | |
Uemura et al. [14] | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 8 | |
Wiggers et al. [18] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Komaya et al. [15] | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 |
Higuchi et al. [16] | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 |
Miura et al. [17] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |