Table 1.
Baseline characteristics and Cox regression analysis for factors associated with injection initiation among street-involved youth (n = 462).
| Baseline Characteristics | Bivariable and Multivariable Cox Regression Analysis | |||||
|---|---|---|---|---|---|---|
|
|
||||||
| Injection Initiation
|
Unadjusted HRa (95% CI)b |
p-value | Adjusted HR (95% CI) |
p-value | ||
| Characteristic | Yes (n=97) n (%) |
No (n=365) n(%) |
||||
| Prescription Opiate Usec,d | ||||||
| Yes | 49 (50.5) | 129 (35.3) | 1.82 (1.22 – 2.70) | 0.003 | 1.70 (1.12 – 2.58) | 0.012 |
| No | 48 (49.5) | 236 (64.7) | ||||
| Age (per year older) | ||||||
| Median IQR | 21.3 (19.6, 22.6) | 21.6 (19.6, 23.4) | 0.96 (0.90 – 1.03) | 0.288 | ||
| Caucasian Ethnicity | ||||||
| Yes | 68 (70.1) | 219 (60.0) | 1.50 (0.97 – 2.31) | 0.069 | ||
| No | 29 (29.9) | 146 (40.0) | ||||
| Female Gender | ||||||
| Yes | 28 (28.9) | 114 (31.2) | 0.96 (0.62 – 1.50) | 0.872 | ||
| No | 69 (71.1) | 251 (68.8) | ||||
| Heroin Used,e,f | ||||||
| Yes | 24 (24.7) | 52 (14.2) | 2.12 (1.34 – 3.36) | 0.001 | 1.66 (1.02 – 2.72) | 0.043 |
| No | 70 (72.2) | 307 (84.1) | ||||
| Cocaine Used,e,f | ||||||
| Yes | 43 (44.3) | 186 (51.0) | 1.17 (0.77 – 1.78) | 0.449 | ||
| No | 52 (53.6) | 176 (48.2) | ||||
| Crack Smokinge,f | ||||||
| Yes | 68 (70.1) | 190 (52.1) | 1.71 (1.11 – 2.63) | 0.015 | ||
| No | 27 (27.8) | 171 (46.8) | ||||
| Crystal Meth Used,e,f | ||||||
| Yes | 51 (52.6) | 122 (33.4) | 2.31 (1.53 – 3.47) | <0.001 | 2.08 (1.37 – 3.17) | <0.001 |
| No | 43 (44.3) | 238 (65.2) | ||||
a
HR: hazard ratio;
b
CI: confidence interval;
c
denotes activities ever;
d
denotes non-injection use;
e
denotes activities in the six months prior to follow-up interview;
f
refers to the activities lagged to the pervious available study follow-up