Table 2.
Methodological quality assessment of the studies by Newcastle–Ottawa Quality Assessment Scale (NOS).
| References | Selection | Comparability | Exposure | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
| Rahman et al., 2020 [17] | * | * | * | * | * | * | * | * | - |
| Laganà et al., 2019 [18] | * | * | * | * | * | * | * | * | - |
| Venza et al., 2019 [19] | * | * | * | * | * | * | * | * | - |
| Hanisch et al., 2018 [20] | * | * | * | * | * | * | * | ||
| Dolci et al., 2016 [21] | * | * | * | - | * | * | - | * | - |
| Suzuki et al., 2015 [22] | * | * | * | - | * | * | * | * | - |
| Suzuki et al., 2014 [23] | * | * | * | - | * | * | * | * | - |
| Staufenbiel et al., 2013 [8] | * | * | * | - | * | * | * | * | - |
| De Coster et al., 2004 [24] | * | * | * | - | * | * | - | * | - |
| De Coster et al., 2002 [9] | * | * | * | - | * | * | - | * | - |
1—Adequate case definition; 2—representativeness of the cases; 3—selections of control/comparator; 4—definitions of control/comparator; 5—case; 6—control/comparator; 7—exposure of evaluation; 8—same method for case and control; 9—non-response rate. (*): Yes; (-): No.