|
Reference
|
Sampling (4 points)
|
Confounders controlled (2 points)
|
Exposure (3 points)
|
Total rating (9 points)
|
|---|
|
[37]
|
– − − −
|
– −
|
+ + −
|
2
|
|
[60]
|
– − − −
|
+ −
|
+ + −
|
3
|
|
[44, 46]
|
+ − − −
|
– −
|
+ + +
|
4
|
|
[41]
|
– − − −
|
+ −
|
+ + +
|
4
|
|
[36, 48]
|
+ − − −
|
+ −
|
+ + +
|
5
|
|
[55]
|
+ + − −
|
– −
|
+ + +
|
5
|
|
[45]
|
+ − − +
|
– −
|
+ + +
|
5
|
|
[38, 39, 47, 51]
|
+ − − −
|
+ +
|
+ + +
|
6
|
|
[42]
|
+ + − −
|
+ −
|
+ + +
|
6
|
|
[43, 53, 56, 57, 58, 61]
|
+ + − −
|
+ +
|
+ + +
|
7
|
|
[40, 49, 52, 62]
|
+ − − +
|
+ +
|
+ + +
|
7
|
|
[50]
|
+ + + −
|
+ +
|
+ + +
|
8
|
- Legend: ‘+’ Quality criterion satisfied; ‘-’ Quality criterion not satisfied or insufficient information to adjudicate as satisfied. Studies with a quality score of seven or above were considered high-quality
