Table 1 Sociodemographic characteristics, patterns of drug use, and sexual behaviours in two cross sectional studies carried out in Barcelona, Madrid, and Seville in 1995 and 2001–03 (%).

	Barcelona		Madrid		Seville
	1995	2002	1995	2002	1995	2002
	207	354	199	427	190	200
Number	%	%	%	%	%	%	p Value†
Sociodemographic characteristics
Mean age	26.1	24.9	26.4	26.3	26.7	25.6
Age ⩽25	35.3	53.1	27.6	32.8	26.8	41.5	***
Men	74.4	69.2	75.9	71.7	83.2	82.5	NS
Foreigners	3.9	18.1	1.5	7.0	0.5	3.5	***
Level of education higher than primary	21.7	65.5	28.1	59.0	14.2	23.5	**
Regular employment	21.7	30.8	26.4	32.3	20.5	31.5	***
Job as main source of income in past 12 months	18.8	33.8	24.6	37.9	17.4	28.5	***
Living mainly in a house or apartment in past 12 months	91.8	81.9	87.9	86.8	83.7	91.5	NS
Prison							NS
Never	56.8	60	63.8	60.2	48.1	55.4
<1 year	18.9	19.7	16.1	19.4	20.6	19.5
⩾1 year	24.3	20.3	20.1	20.4	31.2	25.1
Sexual behaviour (past 12 months)
Two or more sexual partners	70.4	49.2	62.2	41.7	50.3	40.1	***
Sexual relation without condoms	66.7	62.1	66.0	49.4	66.5	52.0	***
Sexual relations for money	15.5	7.9	10.7	11.0	14.5	10.0	*
Patterns of drug use and injecting
<18 years at first heroin use	51.2	53.4	48.2	63.5	47.9	66.5	***
Injecting as first main route of heroin administration	43.5	25.1	36.7	12.4	18.9	5.0	***
⩽5 years since first heroin use	30.0	37.9	32.2	22.7	21.6	25.5	NS
Ever injected	87.9	80.2	70.4	65.1	53.2	33.0	**
Injected in the past 12 months	84.1	75.7	48.2	48.9	31.1	15.5	NS
Injected in the past 30 days	82.1	67.5	31.7	39.8	26.8	10.5	NS
Injecting as current main route of heroin administration (past 30 days)	80.7	64.1	20.3	19.7	20.5	0.0	***

†Comparison between 1995 and 2001–03 in the global sample. NS, not significant. *p<0.05; **p<0.01; ***p<0.001.