Table 1.

Characteristics of participants with concurrent drug use.

	n	%	No. of concurrent drug users	%	P-value
	(n=560)		(n=211, 37.7%)
Gender
Female	89	15.9	32	36.0
Male	471	84.1	179	38.0	0.715
Age (years), 33±6, range 19–55
18–29	160	28.6	58	36.3
30–39	310	55.4	123	39.7
≥40	90	16.1	30	33.3	0.499
Marital status
Single	127	22.7	52	40.9
Married or living with partner	350	62.5	125	35.7
Divorced/separated/widowed	83	14.8	34	41.0	0.465
Education
Elementary school	107	19.1	36	33.6
Junior high	300	53.6	119	39.7
Senior high and above	153	27.3	56	36.6	0.516
Route of drug administration
Intravenous injection	398	71.1	154	38.7
Others	162	28.9	57	35.2	0.437
History of drug use (years), 9.5±4.0, range 1–20
<10	251	44.8	121	39.2
≥10	309	55.2	90	35.9	0.423
Length of treatment (months), 13.5±9.5, range 0.1–48.3
>6	129	23.0	64	49.6
6–18	289	51.6	96	33.2
≥18 months	142	25.4	51	35.9	0.005
Current dose (ml), 42.5±11.7, range 2.0–160.0
<30	131	23.4	37	28.2
30–50	223	39.8	87	39.0
≥50	206	36.8	87	42.2	0.031

Mean ± standard deviation.