Table 2 Quality assessment of included studies
Author/year | Selection | Exposure | Comparability | Total score |
|---|---|---|---|---|
Morris/2006 | 3 | 3 | 1 | 7 |
Ferreira/2010 | 4 | 3 | 1 | 8 |
Kucuk/2010 | 4 | 3 | 1 | 8 |
Ramezanzadeh/2012 | 4 | 3 | 0 | 7 |
Evenson/2014 | 4 | 3 | 1 | 8 |
Palomba/2016 | 4 | 3 | 1 | 8 |
Gaskins/2016 | 4 | 3 | 0 | 7 |