Table 4.
Multinomial logistic regression model of illicit drug use experience (reference group: illicit drug-naïve) on binary ketamine expectancies with adjustment for sociodemographics and early-onset tobacco use (N = 1115)
| Variables | Any ketamine use | The other illicit drug use | ||
|---|---|---|---|---|
| aOR | 95% CI | aOR | 95% CI | |
| Model 1 | ||||
| Male | 1.20 | (0.68–2.12) | 1.27 | (0.71–2.28) |
| Education < college | 1.48 | (0.83–2.61) | 0.82 | (0.45–1.49) |
| Unemployment | 4.76 | (1.59–14.19) | 5.43 | (2.54–11.6) |
| Age in years | 0.94 | (0.91–0.98) | 1.01 | (0.98–1.04) |
| Early-onset tobacco use | 2.39 | (1.36–4.21) | 2.44 | (1.39–4.28) |
| High Positive expectancies | 10.04 | (5.23–19.27) | 3.10 | (1.55–6.22) |
| High Negative expectancies | 0.15 | (0.08–0.26) | 0.40 | (0.21–0.76) |
| Model 2 | ||||
| Male | 1.20 | (0.67–2.14) | 1.26 | (0.7–2.26) |
| Education < college | 1.46 | (0.82–2.61) | 0.81 | (0.45–1.48) |
| Unemployment | 4.70 | (1.60–13.76) | 5.25 | (2.52–10.93) |
| Age in years | 0.94 | (0.91–0.98) | 1.01 | (0.98–1.04) |
| Early-onset tobacco use | 2.45 | (1.37–4.36) | 2.53 | (1.45–4.39) |
| Ketamine expectancy combination (ref: Low Positive-High Negative) | ||||
| Low Positive-Low Negative | 3.58 | (1.13–11.35) | 0.87 | (0.36–2.07) |
| High Positive-High Negative | 5.49 | (1.75–17.23) | 1.24 | (0.56–2.74) |
| High Positive-Low Negative | 43.47 | (14.55–129.86) | 4.87 | (1.96–12.14) |
Note: (1) high or low expectancies are divided by the median of the illicit drug-naïve
(2): statistically significant results are highlighted in bold