Table 3.
Top: Patterns of heroin use before and after initiating prescription opioid injection among initiators (n = 218) and a group of controls matched on initiation period (n = 872); Bottom: Results of four linear growth curve analyses comparing initiators with controls for each heroin use pattern.
| Heroin use* | PO Initiation Period | p value | |
|---|---|---|---|
|
| |||
| Before n (%) | After n (%) | ||
| Daily injection | |||
| PO initiators | 62 (28.4) | 77 (35.3) | 0.075 |
| Controls | 53 (6.1) | 48 (5.5) | 0.466 |
| Any injection | |||
| PO initiators | 135 (61.9) | 149 (68.4) | 0.090 |
| Controls | 148 (17.0) | 133 (15.3) | 0.147 |
| Daily non-injection | |||
| PO initiators | 5 (2.3) | 4 (1.8) | 0.706 |
| Controls | 12 (1.4) | 8 (0.9) | 0.248 |
| Any non-injection | |||
| PO initiators | 27 (12.4) | 29 (13.3) | 0.758 |
| Controls | 73 (8.4) | 47 (5.4) | 0.002 |
|
| |||
| Heroin use* | Slope (95% CI**) | p value*** | |
|
| |||
| Daily injection | |||
| PO initiators | 0.592 (0.046–1.138) | 0.049 | |
| Controls | −0.157 (−0.660–0.346) | ||
| Any injection | |||
| PO initiators | 0.639 (0.072–1.205) | 0.011 | |
| Controls | −0.239 (−0.605–0.127) | ||
| Daily non-injection | |||
| PO initiators | −0.369 (−2.051–1.312) | 0.901 | |
| Controls | −0.498 (−1.640–0.644) | ||
| Any non-injection | |||
| PO initiators | 0.068 (−0.651–0.787) | 0.065 | |
| Controls | −0.751 (−1.240 to−0.262) | ||
*
In the previous 6 months.
**
95% Confidence Interval.
***
Estimates have been adjusted for age, gender, ethnicity, and baseline education, Downtown Eastside residency, addiction treatment, drug dealing, heavy alcohol use, cocaine injection, crack/cocaine non-injection, methamphetamine injection, and cohort membership.