Table 2.

Comparison of characteristics and injecting risk behaviours among injecting drug users in Volgograd and Barnaul (2003–2004) by recruitment method

Characteristic	Barnaul						Volgograd
	IF		RDSa				IF		RDSa
	n/total	%/mean (SD)	n/total	%/mean (SD)	χ2	P value	n/total	%/mean (SD)	n/total	%/mean (SD)	χ2	P value
Total† age (years)		25.8 (8.2)		24.8 (6.1)	2.2	0.03		24.5 (3.9)		23.8 (5.4)	2.3	0.022
Male	348/504	69%	293/365	80%	13.8	<0.001	388/512	76%	317/346	92%	35.3	<0.001
Attended higher education	67/504	13%	136/353	39%	73.1	<0.001	140/509	28%	150/334	45%	27.1	<0.001
Duration of injection (years)		7.1 (6.9)	6.7 (4.3)		1.1	0.29		5.4 (3.4)		6.1 (4.3)	−2.6	0.009
No official residency permit	34/495	7%	7/356	2%	11.2	0.001	19/471	4%	8/338	2%	1.9	0.174
Injecting risk behaviours in the last 4 weeks
Main drug injected
Heroin	280/504	56%	263/357	74%			424/508	83%	328/345	95%
Vint	135/504	27%	38/357	11%			37/508	7%	7/345	2%
Mak	84/504	17%	51/357	14%			21/508	4%	6/345	2%
Other	5/504	1%	5/357	1%	39	<0.001	26/508	5%	4/345	1%	27	<0.001
Daily injection	100/500	20%	69/356	19%	0.05	0.823	86/512	17%	63/341	18%	0.4	0.53
Injected with used needles/syringes	75/500	15%	75/353	21%	5.6	0.018	63/510	12%	37/336	11%	0.35	0.55
Main source of new needles/syringes
Pharmacy	466/498	94%	325/365	89%			463/508	91%	327/341	96%
Treatment	21/498	4%	12/365	3%			33/508	6%	6/341	2%
Other**	11/498	2%	28/365	8%	14.9	0.001	12/508	2%	8/341	2%	10.5	0.005
Ever injected with used needles/syringes	255/481	53%	225/356	63%	8.7	0.003	301/493	61%	137/345	40%	37.1	<0.001

^aThe RDS data are not adjusted for homophily and network effects.

†Numbers do not always add up to total because not all respondents answered each question.

**Other refers to friends, family, found on the street, drug dealers.