TABLE 4.
Mean (SE) for Variables by Usage Groups, With F for ANOVA and Ps for 3 Contrasts From Multinomial Regression
| Variable | Usage Group | F | Contrast (P) | |||||
|---|---|---|---|---|---|---|---|---|
| 1. Nonuser | 2. E-Cigarettes Only | 3. Cigarettes Only | 4. Dual Use | 1 vs 2 | 2 vs 3 | 2 vs 4 | ||
| Social-cognitive protective factors | ||||||||
| Parental support | 25.9 (0.20) | 23.3 (0.40) | 20.0 (0.97) | 21.8 (0.48) | 36.5 | .001 | .01 | .03 |
| Parental monitoring | 21.2 (0.10) | 20.0 (0.20) | 18.7 (0.50) | 19.0 (0.24) | 33.0 | .001 | .04 | .01 |
| Academic involvement | 18.3 (0.11) | 16.6 (0.22) | 15.5 (0.53) | 15.5 (0.26) | 46.7 | .001 | ns | .002 |
| Grades past year | 4.3 (0.02) | 3.9 (0.05) | 3.8 (0.11) | 3.5 (0.06) | 65.1 | .001 | ns | .001 |
| Behavioral self-control | 65.4 (0.32) | 61.2 (0.65) | 57.9 (1.58) | 57.0 (0.77) | 43.2 | .001 | ns | .001 |
| Emotional self-control | 44.3 (0.28) | 40.4 (0.57) | 35.9 (1.42) | 38.9 (0.68) | 33.9 | .001 | ns | ns |
| Social competence | 9.4 (0.08) | 9.7 (0.16) | 8.7 (0.39) | 9.7 (0.19) | 2.5# | ns | ns | ns |
| Social-cognitive risk factors | ||||||||
| Smoker prototype | 8.9 (0.10) | 9.4 (0.20) | 10.1 (0.50) | 10.5 (0.24) | 13.3 | .02 | ns | .01 |
| Smoking expectancies | 8.8 (0.16) | 10.1 (0.31) | 13.3 (0.79) | 14.3 (0.38) | 68.6 | .001 | .002 | .001 |
| Behavioral dysregulation | 38.9 (0.27) | 43.6 (0.54) | 42.6 (1.33) | 45.7 (0.64) | 45.3 | .001 | ns | .02 |
| Emotional dysregulation | 21.7 (0.22) | 24.7 (0.45) | 27.4 (1.11) | 26.7 (0.54) | 37.0 | .001 | .03 | .01 |
| Peer smoking | 0.8 (0.04) | 1.5 (0.08) | 1.9 (0.19) | 2.8 (0.09) | 135.6 | .001 | ns | .001 |
| E-cigarettes healthier | 1.6 (0.01) | 1.8 (0.03) | 1.7 (0.06) | 1.8 (0.03) | 30.3 | .001 | ns | ns |
| Problem behavior risk factors | ||||||||
| Parent–adolescent conflict | 7.6 (0.09) | 8.7 (0.18) | 9.4 (0.46) | 9.5 (0.22) | 29.2 | .001 | ns | .02 |
| Sensation seeking | 13.4 (0.12) | 15.8 (0.24) | 16.8 (0.58) | 17.8 (0.29) | 89.6 | .001 | ns | .001 |
| Rebelliousness | 6.3 (0.09) | 8.4 (0.18) | 9.5 (0.46) | 10.9 (0.22) | 152.7 | .001 | ns | .001 |
| Collateral substance use | ||||||||
| Alcohol use | 0.5 (0.03) | 1.5 (0.06) | 1.9 (0.14) | 2.5 (0.07) | 296.4 | .001 | ns | .001 |
| Marijuana use | 0.1 (0.03) | 0.6 (0.05) | 1.1 (0.13) | 2.6 (0.06) | 474.4 | .001 | ns | .001 |
| Heavy drinking | 0.1 (0.02) | 0.3 (0.03) | 0.4 (0.08) | 0.9 (0.04) | 138.2 | .001 | ns | .001 |
ns, nonsignificant. Usage group sizes are as follows: Nonuser group = 1319 cases; e-cigarette only group = 331 cases; cigarette-only group = 54 cases; and dual-use group = 228 cases. F for ANOVA has approximately 3/1910 degrees of freedom. Fs are significant at P < .001 unless otherwise noted; # indicates not significant. Regressions include control for gender, grade, family structure, ethnicity, and parental education and adjustment for any within-school clustering. For contrasts, 0.001 indicates effect is significant at P < .001; otherwise, exact probability indicates significance level of result.