Table 2.

Demographic characteristics of participants ( N  = 236)

Variables	n (%) or Mean (SD)
Demographic
Age (years)	38.07 (7.44)
Male gender	212 (89.8%)
Living alone	15 (6.4%)a
Years of formal education	9.43 (2.35)
Had fixed employment	125 (53.2%)b
Family history of drug abuse	33 (14.0%)
Medical history
Age at first heroin use	26.13 (6.32)
Duration of heroin use	8.05 (5.85)c
Concurrently use methamphetamine	155 (65.7%)
HIV carrier positive	47 (19.9%)
HBV carrier positive	39 (16.5%)
HCV carrier positive	223 (94.5%)

Human immunodeficiency virus, HIV; hepatitis C virus, HCV; hepatitis B virus, HBV.

^a n = 233 due to missing answers.

^b n = 235 due to missing answers.

^c n = 196 due to missing answers.