Table 2.
Multilevel Models Assessing Physical Context of Substance Use Predicting Odds of SAM Use, by <21 and 21+ Years
| Total Sample | < 21 Years Old | 21 Years and Older | |||
|---|---|---|---|---|---|
| (n = 594 days) | (n = 302 days) | (n = 292 days) | |||
| Model 1 | Level 1 | Intercept | 0.12 [0.05, 0.30]*** | 0.24 [0.07, 0.81]* | 0.05 [0.01, 0.24]** |
| Home | 2.46 [1.37, 4.42]* | 2.94 [1.29, 6.73]* | 2.02 [0.86, 4.77] | ||
| Weekend | 1.05 [0.65, 1.69] | 0.66 [0.33, 1.33] | 1.61 [0.82, 3.18] | ||
| Level 2 | Prop. Home | 2.53 [0.76, 8.44] | 1.22 [0.24, 6.14] | 6.88 [0.97, 48.55] | |
| Sex | 1.56 [0.76, 3.20] | 1.71 [0.65, 4.52] | 1.40 [0.45, 4.38] | ||
|
| |||||
| Model 2 | Level 1 | Intercept | 0.42 [0.23, 0.75]** | 0.58 [0.26, 1.30] | -- |
| Work | 0.76 [0.09, 6.75] | 0.63 [0.05, 7.64] | -- | ||
| Weekend | 1.02 [0.64, 1.62] | 0.64 [0.32, 1.26] | -- | ||
| Level 2 | Prop. Work | 0.02 [0.00, 4.73] | 0.17 [0.00, 25.60] | -- | |
| Sex | 1.70 [0.83, 3.49] | 1.86 [0.71, 4.87] | -- | ||
|
| |||||
| Model 3 | Level 1 | Intercept | 0.25 [0.12, 0.52]*** | 0.50 [0.17, 1.46] | 0.12 [0.04, 0.33]*** |
| Friend’s House | 1.90 [1.07, 3.39]* | 1.60 [0.69, 3.71] | 2.35 [1.06, 5.22]* | ||
| Weekend | 0.93 [0.58, 1.49] | 0.59 [0.30, 1.19] | 1.50 [0.76, 2.96] | ||
| Level 2 | Prop. Friend House | 1.61 [0.52, 4.92] | 0.83 [0.18, 3.87] | 8.87 [1.29, 61.19]* | |
| Sex | 1.56 [0.76, 3.19] | 1.72 [0.66, 4.48] | 1.22 [0.40, 3.70] | ||
|
| |||||
| Model 4 | Level 1 | Intercept | 0.44 [0.24, 0.81]** | 0.55 [0.24, 1.26] | 0.38 [0.14, 1.04] |
| Restaurant | 0.35 [0.11, 1.15] | 1.24 [0.06, 27.10] | 0.27 [0.07, 1.06] | ||
| Weekend | 0.99 [0.61, 1.58] | 0.65 [0.33, 1.29] | 1.53 [0.77, 3.01] | ||
| Level 2 | Prop. Restaurant | 0.82 [0.04, 18.56] | 1.12 [0.00, 804.11] | 0.44 [0.01, 27.49] | |
| Sex | 1.48 [0.72, 3.04] | 1.72 [0.66, 4.52] | 1.21 [0.37, 3.95] | ||
|
| |||||
| Model 5 | Level 1 | Intercept | 0.50 [0.26, 0.97]* | 0.47 [0.20, 1.14] | 0.91 [0.28, 2.96] |
| Bar/Club | 0.57 [0.30, 1.10] | 0.84 [0.26, 2.73] | 0.44 [0.20, 0.99]* | ||
| Weekend | 1.06 [0.66, 1.71] | 0.65 [0.33, 1.28] | 1.85 [0.93, 3.69] | ||
| Level 2 | Prop. Bar/Club | 0.79 [0.24, 2.65] | 2.82 [0.31, 25.26] | 0.19 [0.03, 1.25] | |
| Sex | 1.47 [0.72, 3.00] | 1.91 [0.72, 5.08] | 1.35 [0.43, 4.21] | ||
|
| |||||
| Model 6 | Level 1 | Intercept | 0.40 [0.22, 0.72]** | 0.56 [0.25, 1.25] | 0.30 [0.12, 0.77]* |
| Car | 2.08 [0.30, 14.42] | 3.63 [0.14, 96.25] | 1.33 [0.10, 16.92] | ||
| Weekend | 1.02 [0.64, 1.63] | 0.64 [0.32, 1.26] | 1.59 [0.81, 3.11] | ||
| Level 2 | Prop. Car | 0.54 [0.02, 16.73] | 2.04 [0.00, 2.68] | 0.78 [0.01, 49.99] | |
| Sex | 1.53 [0.75, 3.14] | 1.68 [0.65, 4.37] | 1.32 [0.41, 4.24] | ||
|
| |||||
| Model 7 | Level 1 | Intercept | 0.38 [0.21, 0.71]** | 0.60 [0.26, 1.36] | 0.19 [0.06, 0.53]** |
| Outdoors | 2.05 [1.00, 4.23] | 1.32 [0.35, 4.98] | 2.43 [1.01, 5.85]* | ||
| Weekend | 0.97 [0.61, 1.56] | 0.65 [0.33, 1.29] | 1.45 [0.73, 2.87] | ||
| Level 2 | Prop. Outdoors | 0.74 [0.17, 3.27] | 0.46 [0.06, 3.82] | 5.12 [0.37, 71.64] | |
| Sex | 1.55 [0.76, 3.17] | 1.73 [0.67, 4.48] | 1.62 [0.50, 5.20] | ||
Note. Separate logistic multilevel models predict the odds of engaging in SAM use on a given day compared to days in which they used alcohol but not marijuana; results reflect odds ratios. Models were conducted separately for those under 21 years and 21+ years old. Weekends (Thursdays through Saturdays) were coded as 1 and weekdays (Sundays through Wednesdays) were coded as 0. The model for “work” for participants 21 years old and older did not converge due to low endorsement.
***
p < .001;
**
p < .01;
*
p < .05