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. 2012 Oct 11;13:100. doi: 10.1186/1471-2296-13-100

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 studiesii
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
[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  

i Abstract only.

ii Categories c, g and h did not apply to database studies (−).