Methodological quality evaluation of included studies according to New Castle - Ottawa quality assessment scale: Case-control studies and cross-section studies (NOS).

Table 1: Methodological quality evaluation of included studies according to New Castle - Ottawa quality assessment scale: Case-control studies and cross-section studies (NOS).

*NOS Evaluation (10 ^)**	Included Studies
Case-control studies
SELECTION	Sanders, et al. [9]
Proper case definition
Representativeness of cases	^*
Selection of controls	^*
Definition of controls
COMPARABILITY	^**
EXHIBITION
EXHIBITION	^*
Calibration of the verification method for cases and controls	^*
Non-responders	-
TOTAL	7^*
SELECTION	Burris, et al. [18]	Weber, et al. [16]	Custodio, et al. [15]	Melis, et al. [8]	Weingarten, et al. [10]
Representativeness	-	-	-	^*	^*
Sample size	-	-	-	-	-
Subjects not included in the sample	-	^*	^*	-	^*
Exposure Check	^**	^**	^**	^*	^**
COMPARABILITY	^*	^*	^*	^*	^*
DISCHARGE
Evaluation of the outcome	^*	^*	^*	^*	^*
Statistical analysis	^*	^*	^*	^*	^*
TOTAL	5^*	6^*	6^*	5^*	7^*

The "^*" means the presence of that point is present on the study analyzed, according to NOS scale.