Table 2.
Multinomial logistic regression: baseline predictors of nonmedical prescription opioid use and heroin use over 32 years (ages 18–50; n = 20,575)
| NMPO use only | Heroin use only | Age 18 concurrent use | Age 19/20 NMPO-to-heroin use transition, followed by 40s heroin-to-NMPO use transition | Mid-20s NMPO-to-heroin use transition” | Mid-30s NMPO-to-heroin use transition | |
|---|---|---|---|---|---|---|
| RRR(95% CI) | RRR(95% CI) | RRR(95% CI) | RRR(95% CI) | RRR(95% CI) | RRR(95% CI) | |
| Sex | ||||||
| Male | Reference | Reference | Reference | Reference | Reference | Reference |
| Female | .958(.878, 1.04) | .779(.472, 1.28) | .612 *** (.456, .819) | .571(.192, 1.69) | .593(.207, 1.69) | .920(.341, 2.48) |
| Race | ||||||
| White | Reference | Reference | Reference | Reference | Reference | Reference |
| Non-White | .513 *** (.447, .590) | 1.87 * (1.08, 3.24) | .865(.584, 1.28) | .332(.059, 1.84) | .271(.058, 1.25) | .542(.187, 1.56) |
| GPA | ||||||
| B- or higher | Reference | Reference | Reference | Reference | Reference | Reference |
| C+ or lower | .987(.894, 1.09) | .875(.515, 1.48) | 1.12(.841, 1.49) | 1.63(.684, 3.87) | 2.13(.787, 5.78) | .783(.302, 2.02) |
| Parents Level of Education | ||||||
| Less than a college degree | Reference | Reference | Reference | Reference | Reference | Reference |
| College degree or higher | 1.17 *** (1.07, 1.28) | 1.24(.712, 2.16) | 1.03(.778, 1.38) | 1.27(.497, 3.25) | 1.31(.496, 3.49) | .940(.383, 2.30) |
| Cigarette Use (past 30-day) | ||||||
| No | Reference | Reference | Reference | Reference | Reference | Reference |
| Yes | 1.53 *** (1.39, 1.68) | 1.54(.889, 2.67) | 1.69 *** (1.24, 2.31) | 2.89 * (1.17, 7.18) | 6.70 ** (1.58, 28.4) | 2.64(.915, 7.63) |
| Binge drink (past two-week) | ||||||
| No | Reference | Reference | Reference | Reference | Reference | Reference |
| Yes | 1.43 *** (1.30, 1.57) | 1.36(.771, 2.41) | 2.46 *** (1.74, 3.49) | .984(.320, 3.03) | 1.36(.471, 3.93) | 1.98(.621, 6.33) |
| Marijuana (past 30-day) | ||||||
| No | Reference | Reference | Reference | Reference | Reference | Reference |
| Yes | 2.90 *** (2.62, 3.20) | 6.07 *** (3.08, 11.9) | 5.99 *** (4.09, 8.78) | 9.66 *** (2.97, 31.4) | 2.77(.476, 16.2) | 12.1 * (1.64, 89.4) |
| Urbanicity | ||||||
| Urban | Reference | Reference | Reference | Reference | Reference | Reference |
| Suburban | 1.06(.952, 1.18) | .811(.456, 1.44) | .873(.616, 1.23) | 2.62(.595, 11.5) | .345(.109, 1.09) | .889(.295, 2.67) |
| Rural | .935(.831, 1.05) | .788(.413, 1.50) | .951(.661, 1.36) | 2.38(.660, 8.63) | .430(.093, 1.97) | .464(.147, 1.45) |
| U.S. Region | ||||||
| Northeast | Reference | Reference | Reference | Reference | Reference | Reference |
| Midwest | 1.03(.922, 1.15) | .838(.431, 1.63) | .925(.651, 1.31) | .050 ** (.006, .413) | .533(.115, 2.46) | .219 * (.067, .720) |
| South | .967(.855, 1.09) | 1.11(.463, 1.71) | 1.29(.877, 1.92) | .707(.244, 2.04) | .444(.093, 2.11) | .421(.124, 1.42) |
| West | 1.65 *** (1.44, 1.89) | 1.78(.893, 3.55) | 1.61 * (1.01, 2.57) | .110 * (.013, .915) | 1.82(.341, 9.69) | .548(.158, 1.90) |
| Cohort Year | ||||||
| 1976–1978 | Reference | Reference | Reference | Reference | Reference | Reference |
| 1979–1981 | .945(.846, 1.05) | .864(.464, 1.61) | 523 *** (.373, .723) | .785(.252, 2.44) | 1.04(.294, 3.70) | .516(.215, 1.24) |
| 1982–1984 | .995(.889, 1.11) | .889(.463, 1.71) | .726(.507, 1.03) | .368(.093, 1.45) | .106 * (.013, .839) | .407(.131, 1.26) |
| 1985–1986 | 1.09(.965, 1.24) | .863(.435, 1.71) | .559 * (.356, .877) | .468(.090, 2.43) | .188(.022, 1.58) | .705(.181, 2.74) |
Notes: RRR = relative risk ratios.
p<.05.
p<.01.
p<.001 (all statistically significant values are in bold).
The “No use” group is the reference for the multinomial logistic regression. Unweighted samples sizes are provided (listwise deletion was used to handle missing data across the age 18 predictors). All provided estimates use weights to adjust for attrition at age 50. Models control for sex, race/ethnicity, parents level of education, urbanicity, U.S. region, cohort year, average GPA in their senior year, college aspirations in their senior year, past 30-day cigarette use in their senior year, past two-week binge drinking in their senior year, and past 30-day marijuana use in their senior year.