Table 2.
The Newcastle–Ottawa scale scores of the included cohort studies
| Study | Representativeness of the exposed cohort | Selection of the non-exposed cohort | Ascertainment of the exposure | Demonstration that outcome of interest was not present at the start of study | Comparability | Assessment of outcome | Follow-up long enough for outcome to occur | Adequacy of follow-up of cohorts | Total |
|---|---|---|---|---|---|---|---|---|---|
| Atladóttir et al. (2012) [14] | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 6 |
| Dreier et al. (2016) [6] | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 6 |
| Holst et al. (2015) [47] | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 6 |
| Gustavson et al. (2019) [48] | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 6 |
| Hornig et al. (2018) [21] | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 6 |