Table 1 Clinical data

 18–20

6 (1.6)

1 (0.3)

0.474^c; Χ = 0.54

 21–30

84 (22.7)

65 (21.0)

 31–40

102 (27.6)

87 (28.2)

 41–50

135 (36.5)

117 (37.9)

 51–60

35 (9.5)

37 (12.0)

 61–70

8 (2.2)

2 (0.6)

 Male

275 (75.3)

203 (65.7)

0.006; Χ = 7.5

 Female

90 (24.7)

106 (34.3)

Years of education mean ± SD

10.3 ± 1.7

10.4 ± 1.4

0.751; T = −.32

Years of methadone maintenance treatment mean ± SD

6.8 ± 5.6

8.3 ± 6.2

0.002; T = −3.2

 ≤1

1 (0.3)

3 (1.1)

1.0^b; Χ = 0.007

 ≥1–3

9 (2.7)

9 (3.2)

 ≥3–5

25 (7.6)

15 (5.3)

 ≥5–10

68 (20.6)

39 (13.8)

 ≥10

227 (68.8)

216 (76.6)

Continued use of illegal drugs despite MMT

226 (63.8)

205 (67.9)

0.285; Χ = 1.2

Continued use of multiple illegal drug despite MMT

82 (23.6)

81 (27.6)

0.275; Χ = 1.3

Methadone dose/methadone equivalent (mg)^b mean ± SD

90.0 ± 41.3

99.1 ± 46.9

0.007; T = −2.7

Imprisonment in the past

212 (60.7)

176 (59.1)

0.688; Χ = 1.9

Withdrawal treatment in the past

172 (50.0)

159 (53.5)

0.372; X = 0.8

Comorbid psychiatric disorder^e

90 (26.4)

99 (33.3)

0.06; X = 3.7

Chronic infection

180 (52.2)

144 (48.2)

0.31; X = 1.0

 HIV

18 (5.2)

25 (8.3)

0.117; X = 2.5

 Hepatits C

163 (47.2)

124 (41.5)

0.141; X = 2.1

 Hepatitis B

25 (7.2)

27 (9.0)

0.407; X = 0.6

 Lues

1 (0.3)

2 (0.7)

0.483; X = 0.5