Table 1.

The characteristics of the national methadone clients in Southwest China

Study variable	Number of clients examined	Infection prevalence (%)	χ 2	P
Drug use behaviors
History of intravenous drug use
Yes	2963	35.7	328.6	<0.001
No	3491	16.1
History of sharing syringes
Yes	1166	49.1	433.6	<0.001
No	5292	19.8
History of drug rehabilitation
Yes	2891	25.4	0.2	0.649
No	3567	24.9
Demographic factors
Gender
Males	5537	26.4	36.2	<0.001
Females	921	17.2
Age
< 30	2877	27.5	34.3	<0.001
30-39	2754	24.6
40-49	738	20.2
≥ 50	89	6.7
Marital status
Single	1297	22.4	10.4	0.016
Married	4889	25.7
Divorced	204	23.5
Widowed	68	35.3
Ethnicity
Yi	5355	28.4	184.7	<0.001
Han	1055	8.6
Other	48	18.8
Socioeconomic factors
Employment
Farming,	5151	28.5	161.2	<0.001
Service-sector,	194	7.2
Unemployed	858	12.8
Other	255	11.0
Educational attainment
No schooling	1586	37.3	308.1	<0.001
Primary school	2885	27.2
Junior high school	1402	13.4
Senior high school or above	585	9.7