Table 2.
Scores of the observational studies according to the Newcastle-Ottawa Scale.
| Selection | Comparability | Exposure | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Author | Representativeness of the Exposed Cohort | Selection of the Nonexposed Cohort | Ascertainment of Exposure | Demonstration That the Outcome of Interest Was Not Present at the Start of the Study | Comparability of Cohorts Based on the Design or Analysis | Assessment of Outcome | Was Follow-Up Long Enough for Outcomes to Occur | Adequacy of the Follow-Up of Cohorts | NOS |
| Beppu 2015 [25] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Chung 2017 [16] | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 7 |
| Markovina 2017 [15] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Hoendervangers 2018 [21] | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 7 |
| Hoendervangers 2020 [23] | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 7 |
| Thakur 2020 [27] | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 7 |
| Chapman 2022 [31] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |