Study | Selection | Comparability | Outcome | NOS | |||||
---|---|---|---|---|---|---|---|---|---|
Representativeness of the exposed cohort | Selection of the non exposed cohort | Ascertainment of exposure | Demonstration that outcomes was not present at start of study | Comparability on the basis of the design or analysis | Assessment of outcome | Adequate follow-up duration | Adequate follow-up rate | Overall score | |
Xiao 2014 [28] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
Tola 2017 [29] | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |
GohariTaban 2019 [30] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
GohariTaban 2021 [31] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
Yang 2021 [32] | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |