Table 1 Baseline characteristics of study participants overall and by urbanicity (N = 279)

Sociodemographics

Median age (IQR)

279

40 (35–46)

39 (35–44)

40 (34–47)

.340^a

Gender

279

.283

      Men

210 (75.3%)

110 (78.0%)

100 (72.5%)

      Women

69 (24.7%)

31 (22.0%)

38 (27.5%)

Ethnicity

279

.096

      Kyrgyz

44 (15.8%)

23 (19.9%)

16 (11.6%)

      Russian

150 (53.8%)

76 (53.9%)

74 (53.6%)

      Another ethnicity

85 (30.5%)

37 (26.2%)

48 (34.8%)

Education

279

.260

      < High school

99 (35.5%)

44 (31.2%)

55 (39.9%)

      High school

106 (38.0%)

55 (39.0%)

51 (37.0%)

      > High school

74 (26.5%)

42 (29.8%)

32 (23.2%)

Any unstable housing past 6 months

279

124 (44.4%)

73 (51.8%)

51 (37.0%)

.013

HIV status

279

.002

      HIV-negative

213 (76.3%)

95 (67.4%)

118 (85.5%)

      Known HIV-positive

61 (21.9%)

42 (29.8%)

19 (13.8%)

      Newly diagnosed HIV-positive

5 (1.8%)

4 (2.8%)

1 (0.7%)

Substance use characteristics

Median age at first injection (IQR)

279

20 (17–24)

20 (17–25)

20 (17–23)

.550^a

Injection frequency past 6 months

279

.544^a

      Daily

23 (10.0%)

14 (9.9%)

14 (10.1%)

      More than once a week

76 (27.2%)

38 (27.0%)

38 (27.5%)

      Once a week

64 (22.9%)

29 (20.6%)

35 (25.4%)

      1–3 times a month

111 (39.8%)

60 (42.6%)

51 (37.0%)

Drugs injected past 6 months

 Heroin

266

240 (90.2%)

124 (93.2%)

116 (87.2%)

1.00

 Diphenhydramine

234

142 (60.7%)

70 (60.3%)

72 (61.0%)

.485

 Stimulants

205

15 (7.3%)

10 (9.3%)

5 (5.2%)

.635

 Benzodiazepines

204

24 (11.8%)

18 (12.8%)

6 (6.1%)

.019^b

 Bath salts^c

181

39 (21.5%)

15 (17.0%)

24 (25.8%)

.196

Poly-injection drug use past 6 months

279

.957^a

      Injected 1 drug type

98 (35.1%)

50 (35.5%)

48 (34.8%)

      Injected 2 drug types

108 (38.7%)

53 (37.6%)

55 (39.9%)

      Injected ≥ 3 drug types

73 (26.2%)

38 (27.0%)

35 (25.4%)

Hazardous drinking

277

94 (33.9%)

49 (34.8%)

45 (33.1%)

.770