Table 4.
Weighted, multivariable, Cox proportional hazard model of factors associated with time to self-reported past year heroin use among recipients of prescription opioids from the participating in the VACS, 2002–2012
| Model 1 Main exposure: Receipt of High-Dose Opioid Rx† | Model 2 Main exposure: Receipt of Long-term Opioid Rx† | |||
|---|---|---|---|---|
| Variables | HR* (95% CI) | P-value | HR (95% CI) | P-value |
| High Dose Opioid Rx (ref: low dose) | 2.54 (1.26–5.10) | 0.009 | N/A | N/A |
| Long-Term Opioid Rx ( ref: short-term) | N/A | N/A | 1.09 (0.75–1.57) | 0.645 |
| Sex (ref: Female) | 1.07 (0.27–4.22) | 0.918 | 1.07 (0.24–4.89) | 0.926 |
| Age (ref: ≤42 years) | -- | -- | -- | -- |
| 43 – 49 years | 0.66 (0.41–1.06) | 0.083 | 0.69 (0.42–1.14) | 0.152 |
| 50 – 56 years | 0.56 (0.35–0.90) | 0.016 | 0.62 (0.42–0.92) | 0.018 |
| ≥57 years | 0.61 (0.29–1.28) | 0.190 | 0.74 (0.38–1.45) | 0.384 |
| HIV (infected versus uninfected) | 0.88 (0.63–1.23) | 0.466 | 0.80 (0.54–1.17) | 0.250 |
| HCV (infected versus uninfected) | 2.70 (1.83–3.97) | <0.001 | 3.46 (2.44–4.91) | <0.001 |
| Race (ref: White) | -- | -- | -- | -- |
| Black | 1.55 (0.72–3.34) | 0.334 | 1.50 (0.79–2.87) | 0.218 |
| Hispanic | 0.96 (0.28–3.30) | 0.949 | 1.34 (0.41–4.41) | 0.625 |
| Other | 1.91 (0.55–6.57) | 0.305 | 1.86 (0.72–4.77) | 0.198 |
| Education (ref: High School or Less) | -- | -- | -- | -- |
| Some College or Greater | 0.62 (0.40–0.97) | 0.036 | 0.52 (0.35–0.78) | 0.001 |
| Gross Annual Income (ref: <$6,000) | -- | -- | -- | -- |
| $6,000 - $11,999 | 1.04 (0.70–1.55) | 0.842 | 0.93 (0.64–1.34) | 0.694 |
| $12,000 - $24,999 | 1.03 (0.72–1.47) | 0.863 | 1.07 (0.71–1.59) | 0.753 |
| ≥$25,000 | 0.80 (0.38–1.70) | 0.567 | 0.75 (0.41–1.37) | 0.350 |
| Marital Status (ref: Married/Living w/Partner) | -- | -- | -- | -- |
| Divorced/Separated/Widowed | 1.40 (1.08–1.80) | 0.011 | 1.18 (0.78–1.78) | 0.444 |
| Never Married | 0.93 (0.59–1.45) | 0.931 | 0.84 (0.51–1.40) | 0.842 |
| PTSDᶲ (ever diagnosis vs. none) | 0.84 (0.50–1.39) | 0.501 | 0.82 (0.48–1.40) | 0.475 |
| Depressionᶲ (ever diagnosis vs. none) | 0.69 (0.41–1.15) | 0.155 | 0.63 (0.30–1.29) | 0.206 |
| Pain Interference in Daily Lifeᶲ (any vs. none) | 1.41 (1.17–1.69) | <0.001 | 1.18 (0.89–1.57) | 0.241 |
| Unhealthy alcohol useᶲ, Past Year | 0.96 (0.61–1.49) | 0.844 | 0.79 (0.50–1.24) | 0.306 |
| Smoker (ref: Never) | -- | -- | -- | -- |
| Current | 1.61 (0.61–4.27) | 0.338 | 1.35 (0.40–4..52) | 0.624 |
| Former | 1.01 (0.41–2.47) | 0.986 | 0.67 (0.22–2.08) | 0.491 |
| Any Injection Drug Use with Heroin, lifetime (yes vs no) | 1.78 (1.11–2.86) | 0.017 | 2.66 (1.60–4.41) | <0.001 |
| Opioid Use Disorder (diagnosis vs. none) | 4.47 (2.65–7.55) | <0.001 | 4.67 (2.77–7.88) | <0.001 |
| Marijuana Useᶲ, Past Year (ref: none) | 1.54 (0.83–2.89) | 0.183 | 1.58 (0.89–2.80) | 0.113 |
| Cocaine Useᶲ, Past Year (ref: none) | 13.21 (7.11–24.52) | <0.001 | 15.94 (8.15–31.15) | <0.001 |
| Stimulant Useᶲ, Past Year (ref: none) | 4.63 (2.07–10.39) | <0.001 | 4.06 (1.85–8.92) | <0.001 |
| Ever stayed in homeless shelter (ref: no) | 0.92 (0.64–1.34) | 0.681 | 0.88 (0.60–1.30) | 0.528 |
| Number of close friends/family (ref: none) | -- | -- | -- | -- |
| 1–4 | 0.70 (0.49–0.99) | 0.044 | 0.75 (0.47–1.20) | 0.230 |
| ≥ 5 | 0.37 (0.20–0.69) | 0.002 | 0.48 (0.27–0.87) | 0.016 |
Note:
*
Hazard ratio
ᶲ
Time-updated values
†
Using robust sandwich estimator
HIV = human immunodeficiency virus; HCV = hepatitis C virus; PTSD = post-traumatic stress disorder; Rx=prescription