Table 4.
Relative Risk Ratio for Misuse of Prescription Opioids in Follow-ups 1–3 for Respondents with vs. without Legitimate Prescription Opioid Use by 12th Grade, by Risk Strata (95% Confidence Intervals in Parentheses)
| Strata # | (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) |
|---|---|---|---|---|---|---|---|---|
| Predicted Probability of Opioid Misuse After High School |
0 to <1.75% |
1.75 to <3% |
3 to <5% |
5 to<10% | 10 to <20% |
20 to <30% |
30 to <45% |
>=45% |
| Legitimate prescription opioid use by 12th grade |
.97 (.22–4.29) |
3.01** (1.79 –5.07) |
1.95* (1.15–3.34) |
1.24 (.81–1.91) |
.98 (.66–1.44) |
1.06 (.64–1.73) |
.56 (.31–1.01) |
.86 (.49–1.63) |
p<.05;
p<.01
Note: The risk ratios in stratums 2 and 3 are significantly higher than those in the other stratums combined, as tested with multiplicative interaction terms. Test models included (a) all the predictors in Model 2 of Table 2, (b) an indicator variable for risk stratum and (c) a multiplicative interaction term of the risk stratum indicator and legitimate opioid prescription by 12th grade. In separate models interactions were statistically significant (p<.05) when including an indicator for risk stratum 2, risk stratum 3, and an indicator for risk strata 2 and 3 combined.