Table 2.

General characteristics at entry and during follow-up of 710 HIV-negative and 168 HCV-negative ever-injecting DU included in HIV and HCV analyses, respectively.

	HIV		HCV
At entry
HIV/HCV infection (n at risk)	710	%	168	%
Prevalence HIV infection at entry risk set	–		4	2.4
Prevalence HCV infection at entry risk set	541	76.2	–
Overall HIV incidence (per 100 PY)	1.65
Overall HCV incidence (per 100 PY)			6.78
General characteristics
Steady partner at entry	333	46.9	77	45.8
Median age at entry risk set (years; IQR)	30.0 (27.0–36.0)		29.0 (25.0–33.0)
Female	274	38.6	56	33.3
Dutch nationality	526	74.1	147	87.5
Western European ethnicity	602	84.8	139	82.7
Injecting drug use
Median time since start injecting (years; IQR)	7.21 (3.04–12.1)		2.43 (0.06–7.16)
Injecting in the past 6 months	524	73.8	100	59.5
Among recent injectors injecting more than once a week	429	82.3	53	54.6
Main drug injected
Heroin	94	17.9	33	33.0
Cocaine	77	14.7	14	14.0
Speedball (i.e. combination of heroin and cocaine) other	271	51.7	37	37.0
	82	15.6	16	16.0
Non-injecting drug use
Non-injecting drug use in the past 6 months	497	70.0	149	88.7
Frequency of non-injecting drug use
Once or more times daily	190	38.2	77	51.7
Once or more times weekly, but less than once or more times daily	188	37.8	61	41.0
Less than weekly	119	23.9	11	7.4
Main non-injecting drug use at entry
Heroin	239	48.2	66	44.2
Cocaine	215	43.3	73	49.0
Other	42	8.5	10	6.7
Follow-up
Median number of visits at risk (IQR)	17 (8–29)		15 (8–28)
Median number of PY (IQR)	8.13 (4.25–13.0)		3.56 (1.15–7.91)
Median number of days between follow up visits (IQR)	128 (118–168)		128 (119–166)

PY = person years; IQR = interquartile range.