Table 1 Quality of the included cohort studies (The Newcastle–Ottawa Scale)
Study | Selection | Comparability | Outcome | Total score | |||||
|---|---|---|---|---|---|---|---|---|---|
Representativeness of the exposed cohort | Selection of the non exposed cohort | Ascertainment of exposure | Demonstration that 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 | ||
Yaroustovsky [23] | ☆ | ☆ | ☆ | ☆ | ☆☆ | ☆ | ☆ | ☆ | 9 |
Mariano [25] | ☆ | ☆ | ☆ | ☆ | ☆☆ | ☆ | ☆ | ☆ | 9 |