Table 1.

Baseline characteristics of PWID with multiple blood samples and single samples (excluded)

Factor	Multiple blood sample (n = 461)	Single blood sample (n = 91)
Age (years), mean (s.d.)	29·5 (4·9)	29·2 (5·0)
Male gender, n (%)	296 (64·2)	60 (65·9)
Injecting career (years), mean (s.d.)	10·8 (5·3)	10·2 (5·5)
Needle-sharing past month, n (%)	39 (9·9)	5 (6·9)
Injecting at least daily, n (%)	277 (60·4)	62 (68·1)
Current opioid substitution therapy, n (%)	268 (58·1)	38 (41·8)*

PWID, People who inject drugs.

Some variables have missing data.

* P < 0·01.