Table 2.

Results of the critical appraisal of included studies

Study	Representativeness of sample	Ascertainment of alcohol consumption	Ascertainment of AI medications (classified)	Ascertainment of AI medications (measured)	Assessment of the outcome (concurrent use)	Study total:
a) Cross Sectional Studies Outcome of Interest Concurrent use of alcohol and medications:
Adams et al. 1995 [18]		++	+			+++
Aira et al. 2005 [19]	+	++		++		+++++
Breslow et al. 2015 [20]	++	++	++	++	++	++++++++++
Cousins et al. 2014 [21]	++	++	++	++	++	++++++++++
Del Rio et al. 1996 [23]	+	++				+++
Del Rio et al. 2002 [22]	+	++	++			+++++
Du et al. 2008 [14]	+	++	++	++	++	+++++++++
Forster et al. 1995 [24]	++	+		++		+++++
Ilomaki et al. 2008 [25]	+	++	++	++	++	+++++++++
Ilomaki et al. 2013 [26]	+	++	++	++	++	+++++++++
Immonen et al. 2012 [27]	++	+	++			+++++
John et al. 2007 [28]	+	+	++	++		++++++
Lagnaoui et al. 2001 [36]			++			++
Onder et al. 2002 [29]		+				+
Pringle et al. 2005 [30]		+	++	++		+++++
Sheahan et al. 1995 [32]		+	++	++		+++++
Qato et al. 2015 [31]	+	++	++	++	++	+++++++++
Swift et al. 2007 [33]	+					+
Veldhuizen et al. 2009 [34]	+	++	++	++	++	+++++++++
Wong et al. 2016 [35]