Table 2.
Quality assessment of the 14 included studies.
| Selection | Outcome | |||||||||
| Study (author, year) | Exposed cohort | Nonexposed cohort | Ascertainment of exposure | Outcome of interest | Comparability | Assessment of outcome | Length of followup | Adequacy of follow-up | Total | |
| Jaaskelainen et al (2012) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Sugimori et al (1998) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 7 | ||
| Uemura et al (2014) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Byrne et al (2016) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Odegaard et al (2013) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 7 | ||
| Cahill et al (2013) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Mekary et al (2013) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Rong et al (2019) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Wennberg et al (2014) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 7 | ||
| Yokoyama et al (2016) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Kubota et al (2016) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Mekary et al (2012) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Wijtzes et al (2016) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 | |
| Kim et al (2015) | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | ∗ | 8 |
∗
1 point. Total, total score.