Table 3.
Parameter estimates from mixed-effects models for change in sexual risk from T1 to T2.
| Variables | Unconditional model Beta (SE) |
Model 1: level 1 Beta (SE) |
Model 2a: main effects model Adjusted beta (SE) |
Model 3a: interaction model Adjusted beta (SE) |
|
| Fixed effect | |||||
| Intercept (γ00) | 0.584 (0.040) (P<.001) | 0.432 (0.045) (P<.001) | 0.801 (0.263) (P=.004) | 0.758 (0.256) (P=.003) | |
| Time (γ10) | 0.303 (0.046) (P<.001) | 0.256 (0.061) (P<.001) | 0.252 (0.058) (P<.001) | ||
| More than 100 SMS per day | 0.384 (0.080) (P<.001) | 1.088 (0.300) (P<.001) | |||
| SMS to whom | |||||
| Parents | −0.084 (0.074) | − | |||
| Boyfriend or girlfriend | 0.160 (0.080) (P=.01) | 0.148 (0.079) | |||
| Number of SNS accounts | 0.018 (0.024) | − | |||
| Number of SNS activities performed | 0.028 (0.024) | − | |||
| Parental monitoring | −0.140 (0.053) (P=.006) | −0.077 (0.064) | |||
| 100 SMS × parental monitoring | −0.237 (0.098) (P=.009) | ||||
| Female | −0.219 (0.090) (P=.01) | −0.218 (0.089) (P=.008) | |||
| Age | 0.177 (0.046) (P=.001) | 0.187 (0.046) (P<.001) | |||
| Random effect | |||||
| Participant | 0.771 (0.035) | 0.785 (0.034) | 0.729 (0.044) | 0.746 (0.041) | |
| Residual σ2 | 0.737 (0.022) | 0.705 (0.021) | 0.616 (0.034) | 0.612 (0.032) | |
| LL ratio | −1547.279 | −1523.1006 | −813.11182 | −853.34291 | |
a Models 2 and 3 control for age, gender, survey language, and intervention type. Age and gender were statistically significant so these variables are presented in the tables. The other control variables were not statistically significant. SMS use and having an SNS account were omitted from the final model due to collinearity with high SMS and number of SNS accounts.