Table 2.
The Newcastle–Ottawa scale for quality assessment of included studies
| Studies | Selection | Comparability | Outcomes | Total score | |||||
|---|---|---|---|---|---|---|---|---|---|
| Representativeness of the exposed cohort | Selection of the non-exposed cohort | Ascertainment of exposure | Outcome of interest was not present at start of study | Based on the design or analysis | Assessment of outcome | Follow-up long enough for outcomes to occur | Adequacy of follow-up of cohorts | ||
| Choo et al. [14] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Di Pierro et al. [15] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 0 | 8 |
| Lo et al. [16] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 0 | 8 |
| Doumerc et al. [17] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 0 | 8 |
| Rocco et al. [18] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Krambeck et al. [19] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 0 | 8 |