Table 1.
Baseline demographics of the study population stratified by daily cocaine injection in the past 6 months (n = 2330)
| Characteristic | Total (%) | Daily cocaine injection | |||
|---|---|---|---|---|---|
| Yes (%) | No (%) | Odds ratio (95% CI) | pvalue | ||
| (n= 2330) | (n= 1588) | (n= 728) | |||
| HIV serostatus | |||||
| Positive | 640 (27.5) | 212 (29.1) | 426 (26.8) | 1.12 (0.92 – 1.36) | 0.247 |
| Negative | 1688 (72.5) | 515 (70.7) | 1161 (73.1) | ||
| Gender | |||||
| Male | 1550 (66.5) | 444 (61.0) | 1098 (69.1) | 0.70 (0.58 – 0.84) | <0.001 |
| Female | 780 (33.5) | 284 (39.0) | 490 (30.9) | ||
| Ethnicity | |||||
| Caucasian | 1424 (61.1) | 413 (56.7) | 1001 (63.0) | 0.77 (0.64 – 0.92) | 0.004 |
| Other | 906 (38.9) | 315 (43.3) | 587 (37.0) | ||
| Unstable housing* | |||||
| Yes | 1637 (70.3) | 556 (76.4) | 1072 (67.5) | 1.62 (1.32 – 1.99) | <0.001 |
| No | 677 (29.1) | 163 (22.4) | 509 (32.1) | ||
| Median age (IQR) | |||||
| Per 10 year older | 37.3 (14.3) | 35.3 (13.4) | 38.4 (14.1) | 0.76 (0.69 – 0.83) | <0.001 |
| Median time since first injection (IQR) | |||||
| Per 10 year longer | 14.4 (18.0) | 14.1 (16.3) | 14.6 (18.8) | 0.91 (0.84 – 0.99) | 0.033 |
| Daily alcohol use* | |||||
| Yes | 550 (23.6) | 179 (24.6) | 368 (23.2) | 1.10 (0.88 – 1.33) | 0.450 |
| No | 1775 (76.2) | 547 (75.1) | 1217 (76.6) | ||
| Daily heroin injection* | |||||
| Yes | 901 (38.7) | 345 (47.4) | 555 (35.0) | 1.68 (1.40 – 2.00) | <0.001 |
| No | 1424 (61.1) | 383 (52.6) | 1033 (65.1) | ||
| Daily heroin (non-injection)* | |||||
| Yes | 97 (4.2) | 30 (4.1) | 66 (4.2) | 0.99 (0.64 – 1.54) | 0.969 |
| No | 2230 (95.7) | 697 (95.7) | 1520 (95.7) | ||
| Daily amphetamine injection* | |||||
| Yes | 51 (2.2) | 7 (1.0) | 44 (2.8) | 0.34 (0.15 – 0.76) | 0.006 |
| No | 2274 (97.6) | 721 (99.0) | 1542 (97.1) | ||
| Daily amphetamine (non-injection)* | |||||
| Yes | 7 (0.3) | 1 (0.1) | 6 (0.4) | 0.36 (0.04 – 3.02) | 0.445† |
| 2322 (99.7) | 727 (99.9) | 1581 (99.6) | |||
| Daily crack cocaine smoking* | |||||
| Yes | 560 (24.0) | 137 (18.8) | 420 (26.5) | 0.65 (0.52 – 0.80) | <0.001 |
| No | 1767 (75.8) | 589 (80.9) | 1167 (73.5) | ||
| Daily speedball injection* | |||||
| Yes | 288 (12.4) | 216 (29.7) | 71 (4.5) | 9.01 (6.77 – 12.00) | <0.001 |
| No | 2038 (87.5) | 512 (70.3) | 1516 (95.5) | ||
*Refers to activities in the six months prior to interview. IQR = Interquartile range. †Fisher’s Exact Test.