treatment and had shorter durations of drug use than HDs, and there was no significant difference between MDs and M/HDs in these variables. Incomes and main administration route in the past years differed in each pairwise comparisons. MDs had the highest income state, followed by M/HDs and HDs. MDs all chose nasal inhalation as the main administration route, but most HDs chose injection. No significant differences were found in education, marital status and employment rates among three groups. (Table 1).Table 1Demographic characteristicsCharacteristics, n (%)MDs (n = 346)HDs (n = 698)M/HDs (n = 247) F/χ2 P Age (M ± SD years)a,c 32.07 ± 7.1933.33 ± 6.6831.93 ± 7.035.86 0.003 Education5.630.228 Less than junior high school81 (23.41)134 (19.20)61 (24.70) Junior high school192 (55.49)390 (55.87)134 (54.25) Senior high school or higher73 (21.10)174 (24.92)52 (21.05)Marital status8.930.063 Married, remarried, or cohabiting143 (41.33)236 (33.81)90 (36.44) Widowed, separated, or divorced67 (19.36)132 (18.91)56 (22.67) Never married136 (39.31)330 (47.28)101 (40.89)Employment Unemployed/illegal work174 (50.29)353 (50.57)126 (51.01)0.030.985 legal work172 (49.71)345 (49.93)121 (48.99)Income past year (¥)a,b,c 222.76 <0.001 0–999915 (4.34)256 (36.68)28 (11.34) 10,000–29,99933 (9.54)129 (18.48)41 (16.60) 30,000–99,999152 (43.93)210 (30.09)104 (42.11) > 100,000146 (42.20)103 (14.76)74 (29.96) Duration of drug use (M ± SD, years)a,c 8.23 ± 11.5110.00 ± 4.637.79 ± 5.0112.10 <0.001 Main
