Table 2 Quality scores of included studies
Reference number | Year | External validity | Internal validity | Informativity | Disagree | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
a | b | c | d | e | sum | f | g | h | i | j | sum | k | l | m | n | o | sum | |||
Questionnaire studies | ||||||||||||||||||||
[23] | 2008 | 0 | 1 | 1 | 0 | 1 | 3 | 1 | 0 | 1 | 1 | 1 | 4 | 1 | 1 | 1 | 1 | 1 | 5 | d,f,h |
[18] | 2008 | 0 | 0 | 0 | 1 | 1 | 2 | 1 | 0 | 1 | 1 | 0 | 3 | 1 | 1 | 1 | 1 | 1 | 5 | g |
[26] | 2008 | 1 | 1 | 0 | 1 | 0 | 3 | 1 | 0 | 0 | 1 | 1 | 3 | 1 | 1 | 1 | 0 | 0 | 3 | n |
[17] | 2007 | 1 | 1 | 0 | 0 | 0 | 2 | 1 | 1 | 0 | 1 | 0 | 3 | 1 | 1 | 1 | 0 | 0 | 3 | d,n |
[7] | 2005 | 1 | 1 | 1 | 1 | 0 | 4 | 1 | 1 | 0 | 1 | 1 | 4 | 1 | 1 | 1 | 1 | 1 | 5 | |
[6] | 2003 | 0 | 1 | 1 | 1 | 0 | 3 | 1 | 0 | 0 | 1 | 1 | 3 | 0 | 1 | 1 | 1 | 1 | 4 | |
[15]i | 2002 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 2 | 0 | 1 | 1 | 0 | 0 | 2 | d,k |
[16] | 1998 | 1 | 1 | 0 | 1 | 0 | 3 | 1 | 1 | 0 | 1 | 0 | 3 | 1 | 1 | 1 | 1 | 1 | 5 | |
[20] | 1996 | 1 | 1 | 1 | 1 | 1 | 5 | 1 | 1 | 1 | 1 | 1 | 5 | 0 | 1 | 1 | 1 | 1 | 4 | i |
[25] | 1996 | 0 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 0 | 3 | 0 | 1 | 1 | 1 | 1 | 4 | d |
[19] | 1995 | 1 | 1 | 1 | 1 | 1 | 5 | 1 | 0 | 1 | 1 | 1 | 4 | 0 | 1 | 1 | 1 | 1 | 4 | l,o |
[22] | 1995 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 3 | 1 | 1 | 0 | 1 | 1 | 4 | i,m |
Database studies ii | ||||||||||||||||||||
[14] | 2006 | 1 | 1 | - | 0 | 1 | 3 | 0 | - | - | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 5 | d |
[24] | 2000 | 1 | 1 | - | 1 | 1 | 4 | 0 | - | - | 1 | 1 | 2 | 0 | 1 | 1 | 1 | 1 | 4 | |
[21] | 1998 | 1 | 1 | - | 0 | 1 | 3 | 0 | - | - | 1 | 1 | 2 | 1 | 1 | 1 | 1 | 1 | 5 | |