Table 3.
Longitudinal Multilevel Regression Model with Frequency of Cigarette Use as the Dependent Variable
| Predictor | Frequency of Cigarette Use (days used in last month) | |||
|---|---|---|---|---|
| Est. (SE) | df | t | p-value | |
| Intercept | 1.25 (0.80) | 1093.60 | 1.55 | .12 |
| Time (linear) | 0.99 (0.06) | 1109.96 | 15.48 | <.001 |
| Gender+ | 0.54 (0.45) | 1106.02 | 1.21 | .23 |
| Ethnicity/Race | 0.81 (0.19) | 1071.98 | 4.35 | <.001 |
| Time-varying predictors | ||||
| Depression (CES-D Total)+ | 0.01 (0.02) | 5086.99 | 0.26 | .61 |
| Marijuana use (frequency of use in last month) |
0.32 (0.02) | 5078.23 | 13.51 | <.001 |
| Interactions | ||||
| Time*Depression+ | 0.01 (0.01) | 4751.40 | 1.88 | .06 |
| Time*Marijuana Use | −0.02 (0.01) | 4784.57 | −2.62 | .01 |
| Gender*Depression+ | 0.01 (0.03) | 5058.98 | 0.21 | .83 |
| Gender*Marijuana Use+ | −0.05 (0.05) | 5122.14 | −0.90 | .37 |
| Depression*Marijuana Use+ | 0.00 (0.00) | 5213.23 | −0.04 | .97 |
| Time*Gender*Depression+ | 0.00 (0.01) | 4751.02 | −0.08 | .94 |
| Time*Gender*Marijuana Use+ | −0.01 (0.01) | 4831.76 | −0.46 | .65 |
| Gender*Depression*Marijuana Use+ | 0.00 (0.00) | 5207.02 | 0.35 | .72 |
Note. CES-D, Center for Epidemiological Scale-Depression;
+
variable removed from final reduced model.