Table 2.
Results of quality assessment using the Newcastle–Ottawa Scale for cohort studies
| Study | Selection | Comparability | Outcome | Scores | |||||
|---|---|---|---|---|---|---|---|---|---|
| Representa-tiveness of exposure |
Selection of the non- exposure |
Ascertainment of exposure | Demonstration that outcome was not present at start | Cohorts on the basis of the design or analysis | Assessment | Long follow-up for outcomes to occur | Adequacy of follow up | ||
| Isong, 2014 [15] | ★ | ★ | ★ | ★ | ★ ★ | ★ | ★ | ★ | 9 |
| Stein, 2014 [7] | ☆ | ★ | ★ | ★ | ★ ★ | ★ | ★ | ★ | 8 |
| Cermak,2015 [16] | ★ | ★ | ★ | ★ | ★ ★ | ★ | ★ | ★ | 9 |
| G.Lefer,2018 [13] | ★ | ★ | ★ | ★ | ★ ★ | ☆ | ★ | ★ | 8 |
| YePark, 2022 [22] | ★ | ★ | ★ | ★ | ★ ★ | ☆ | ★ | ★ | 8 |
| Fallea, 2022 [29] | ☆ | ★ | ★ | ★ | ★ ★ | ☆ | ★ | ★ | 7 |
Comparability has two scores, and the other items only have one score. The black stars symbol means yes, or the white stars symbol means no