Table 1.

Studies analysed.

First author (citation)	Year	Country	n	Proportion of patients who drink	Proportion of patients who are female	Proportion of patients who smoke	Strobe Score
Bergman15	2013	Sweden	1238	0.887	0.7	0.17	18
Bergstrom9	2013	Sweden	172	0.894	0.791	0.385	18
Bing16	2013	US	615	0.666	0.829	0.0846	18
Gunter24	2017	S. Africa	177	0.316	0.825	0.102	16
Larsson25	2018	Sweden	1509	0.904	0.71	Not reported	19
Mangnus26	2018	Netherlands	380	0.644	0.644	0.284	19
Marshall27	2013	US	166	0.608	0.855	0.259	20
Maxwell13	2010	UK	873	0.708	0.722	0.594	19
Nissen28	2010	Switzerland	2908	0.627	0.7542	0.2666	18
Pala29	2013	US	2764	0.403	0.816	Not reported	N/A
Sageloli30	2018	France	596	0.173	0.775	0.209	15
Shimizu31	2017	Japan	4695	0.506	0.866	Not reported	N/A
Taşpınar32	2018	Turkey	56	0.089	0.84	0.375	15
Yoshimura33	2019	Japan	198	0.364	0.843	0.298	N/A