Table 2.
Quality assessment of the included cohort studies
| Newcastle-Ottawa Scale for assessing the quality of cohort studies in meta-analysis | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Selection | Comparability | Outcome | |||||||||
| Study | Representativeness of the exposed cohort | Selection of the non-exposed cohort | Ascertainment of exposure | Demonstration that the current outcome of interest was not present at start of study | Comparability of cohorts on the basis of the design or analysis | Assessment of outcome | Was follow-up long enough for outcomes to occur | Adequacy of follow up of cohorts | Quality score | ||
| 1 | Feskanich | 2014 | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | ||
| 2 | Michaëlsson | 2014 | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 |
| 3 | Sahni | 2014 | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 |
| 4 | Feart | 2013 | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | ||
| 5 | Benetou | 2011 | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | ||
| 6 | Cumming | 1997 | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | ||
| 7 | Fujiwara | 1997 | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 |
| 8 | Meyer | 1997 | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 |
| 9 | Owusu | 1997 | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | ||
A study can be awarded a maximum of one star for each numbered item within the Selection and Outcome categories. A maximum of two stars can be given for Comparability