Studies | Jadad questions | Total score | ||||||
1 | 2 | 3 | 4 | 5 | 6 | 7 | ||
Wisham (1953) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Bjerre-Jepsen (1984) | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
Wu (1996) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Fan (2005) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Ou (2006) | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
Zhu (2006) | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
Guan (2007) | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
Jiang (2009) | 1 | 0 | 0 | 0 | 0 | −1 | 0 | 0 |
Zhang (2009) | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 2 |