Table 2.
Newcastle–Ottawa scale ratings for included studies
| Study | Selection | Comparability | Outcome | Total score and quality | |||||
|---|---|---|---|---|---|---|---|---|---|
| Representativeness of exposed cohort (one star) | Selection of non-exposed cohort (one star) | Ascertainment of exposure (one start) | Outcome of interest does not present at start of star (one star) | One or two stars | Assessment of outcome (one star) | Length of follow up adequate for outcome (one star) | Adequacy of follow up (one star | ||
| Bennet et al. [22] | * | * | * | * | * | * | * | * | 8 Good |
| Berger et al. [27] | * | * | * | * | * | * | * | * | 8 Good |
| Beyene et al. [39] | * | * | * | * | * | * | * | 8 Good | |
| Bicket et al. [30] | * | * | * | * | ** | * | * | 8 Good | |
| Brescia et al. [23] | * | * | * | * | * | * | * | * | 8 Good |
| Brescia et al. [24] | * | * | * | * | * | * | * | * | 8 Good |
| Brown et al. [33] | * | * | * | * | * | * | * | * | 8 Good |
| Brummet et al. [19] | * | * | * | * | * | * | * | * | 8 Good |
| Clement et al. [36] | * | * | * | * | * | * | * | * | 8 Good |
| Clement et al. [35] | * | * | * | * | * | * | * | * | 8 Good |
| Clement et al. [34] | * | * | * | * | * | * | * | * | 8 Good |
| Delaney et al. [38] | * | * | * | * | * | * | * | * | 8 Good |
| Gil et al. [28] | * | * | * | * | * | * | * | * | 8 Good |
| Gossett et al. [31] | * | * | * | * | * | * | * | * | 8 Good |
| Harbaugh et al. [21] | * | * | * | * | * | * | * | * | 8 Good |
| Johnson et al. [18] | * | * | * | * | * | * | * | * | 8 Good |
| Lee et al. [20] | * | * | * | * | * | * | * | * | 8 Good |
| Roughead et al. [26] | * | * | * | * | * | * | 6 Poor | ||
| Santosa et al. [37] | * | * | * | * | * | * | * | * | 8 Good |
| Thiels et al. [25] | * | * | * | * | * | * | * | * | 8 Good |
| Ward et al. [32] | * | * | * | * | * | * | * | * | 8 Good |
| Wright et al. [29] | * | * | * | * | * | * | * | * | 8 Good |