Table 3.

Prevalence of risk factor combinations

First risk factor	Second risk factor
	het		hrh		sti		idu		hcv		hbv		msm		nos		pen		Total N
	N	Row %	N	Row %	N	Row %	N	Row %	N	Row %	N	Row %	N	Row %	N	Row %	N	Row %	N	Row %
het	2219	100.0%	1201	54.1%	836	37.7%	989	44.6%	1159	52.2%	981	44.2%	100	4.5%	333	15.0%	1301	58.6%	2219	100.0%
hrh	1201	100.0%	1201	100.0%	534	44.5%	775	64.5%	783	65.2%	608	50.6%	45	3.7%	129	10.7%	817	68.0%	1201	100.0%
sti	836	96.3%	534	61.5%	868	100.0%	438	50.5%	475	54.7%	439	50.6%	58	6.7%	109	12.6%	601	69.2%	868	100.0%
idu	989	97.4%	775	76.4%	438	43.2%	1015	100.0%	835	82.3%	628	61.9%	33	3.3%	98	9.7%	698	68.8%	1015	100.0%
hcv	1159	98.1%	783	66.3%	475	40.2%	835	70.7%	1181	100.0%	779	66.0%	37	3.1%	154	13.0%	759	64.3%	1181	100.0%
hbv	981	96.7%	608	60.0%	439	43.3%	628	61.9%	779	76.8%	1014	100.0%	60	5.9%	143	14.1%	634	62.5%	1014	100.0%
msm	100	76.9%	45	34.6%	58	44.6%	33	25.4%	37	28.5%	60	46.2%	130	100.0%	16	12.3%	72	55.4%	130	100.0%
nos	333	95.7%	129	37.1%	109	31.3%	98	28.2%	154	44.3%	143	41.1%	16	4.6%	348	100.0%	225	64.7%	348	100.0%
pen	1301	97.2%	817	61.1%	601	44.9%	698	52.2%	759	56.7%	634	47.4%	72	5.4%	225	16.8%	1338	100.0%	1338	100.0%

The Row % shows the prevalence of second risk factor among patients reporting the first risk factor

Risk factors (for definitions see Table 1): het heterosexual exposure, hrh high-risk heterosexual exposure, sti sexually transmitted infections, idu injecting drug use, hcv exposure to HCV, hbv exposure to HBV, msm homosexual exposure, nos nosocomial exposure, pen skin penetration exposure