Table 2.
Study quality evaluation via the Newcastle-Ottawa scale
| Studies | Adequate definition of cases | Representativeness of cases | Selection of controls | Definition of controls | Control for age and sex | Control for other confounders | Exposure ascertainment | Same methods for events ascertainment | Non-response rates | Total |
|---|---|---|---|---|---|---|---|---|---|---|
| Mehla 2012 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 6 |
| Yuan 2013 treated | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Yuan 2013 untreated | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Yuan 2015 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Schrier 2015 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 9 |
| Kallianpur 2019 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 9 |
| Ozturk 2019 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Burlacu 2020 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 9 |
| De Almeida 2022 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Guha 2023 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 7 |
| Hu 2024 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 7 |
| Diaz 2025 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |