Table 1 Demographic characteristics

Age (M ± SD years)^a,c

32.07 ± 7.19

33.33 ± 6.68

31.93 ± 7.03

5.86

0.003

Education

5.63

0.228

 Less than junior high school

81 (23.41)

134 (19.20)

61 (24.70)

 Junior high school

192 (55.49)

390 (55.87)

134 (54.25)

 Senior high school or higher

73 (21.10)

174 (24.92)

52 (21.05)

Marital status

8.93

0.063

 Married, remarried, or cohabiting

143 (41.33)

236 (33.81)

90 (36.44)

 Widowed, separated, or divorced

67 (19.36)

132 (18.91)

56 (22.67)

 Never married

136 (39.31)

330 (47.28)

101 (40.89)

 Unemployed/illegal work

174 (50.29)

353 (50.57)

126 (51.01)

0.03

0.985

 legal work

172 (49.71)

345 (49.93)

121 (48.99)

Income past year (¥)^a,b,c

<0.001

 0–9999

15 (4.34)

256 (36.68)

28 (11.34)

 10,000–29,999

33 (9.54)

129 (18.48)

41 (16.60)

 30,000–99,999

152 (43.93)

210 (30.09)

104 (42.11)

  > 100,000

146 (42.20)

103 (14.76)

74 (29.96)

 Duration of drug use (M ± SD, years)^a,c

8.23 ± 11.51

10.00 ± 4.63

7.79 ± 5.01

12.10

<0.001

Main administration route (past-year)^a,b,c

 Injection

0

138 (19.77)

211 (85.43)

 Nasal inhalation

346(100.00)

560 (80.23)

36 (14.57)

Previous detoxification treatment^a,c

 Yes

187 (54.04)

642 (91.98)

133 (53.85)

 No

159 (45.95)

56 (8.02)

114 (46.15)

Family history of substance use^a,c

90.42

<0.001

 Yes

65 (18.79)

312 (44.70)

52 (21.05)

 No

281 (81.21)

386 (55.30)

195 (78.95)