Question Study
Case control Cross sectional
Waller et al.
[32]		 Stott-Miller et al.
[46]		 Watkins et al.
[58]		 Block et al.
[59]		 Marengo et al.
[60]
1.“Did the study address a clearly focused issue?” Yes Yes Yes Yes Yes
2.”Did the authors use an appropriate method to answer their question? Yes Yes Yes Yes Yes
3.“Were the cases recruited in a acceptable way?” Yes Yes Yes Yes Yes
4.”Were the controls selected in an acceptable way?” Yes Yes Can’t tell
(response rate
was not reported)		 N/A N/A
5.“Was the exposure accurately measured to minimize bias?” Yes Yes Yes Yes Yes
6a.”What confounding factors have the authors accounted for?” As shown in
Table 4 		As shown in
Table 4 		As shown in
Table 4 		As shown in
Table 4 		As show in
Table 4
6b.”Have the authors taken account of the potential confounding factors?” Yes No Yes No No
7.“What are the results of this study?” As shown in
Tables 7A and 8A		 As shown in
Tables 7A and 8A		 As shown in
Tables 7A and 8A		 As shown in
Tables 7B and 8B		 As shown in
Tables 7B and 8B
8.“How precise is the estimate of risk?” As shown in
Tables 7A and 8A		 As shown in
Tables 7A and 8A		 As shown in
Tables 7A and 8A		 As shown in
Tables 7B and 8B		 As shown in
Tables 7B and 8B
9.“Do you believe the result?” Yes Yes Yes Yes Yes
10.“Can the results be applied to the local population?” Yes Yes Yes Yes No
11.“Do the result of the study fit with other available evidence?” Yes Yes No Yes Yes

N/A = not applicable.