Table 5.
Model fit statistics, standardized factor loadings, and factor correlations for alternate models of drug use.
| Statistics, loadings, and correlations | Bifactor | Correlated Factors | |||||
|---|---|---|---|---|---|---|---|
| Statistic | Model fit | Model fit | |||||
| Chi-square (WLSMV) | 540.909 | 959.605 | |||||
| Degrees of freedom | 68 | 81 | |||||
| Comparative fit index | 0.993 | 0.987 | |||||
| Tucker-Lewis index | 0.988 | 0.982 | |||||
| RMSEA (90% CI) | 0.014 (0.013–0.015) | 0.017 (0.016–0.018) | |||||
| Standardized factor loading (SE) | General | Uppers | Downers | All-Arounders | Uppers | Downers | All-Arounders |
| Prescription opioids | 0.735 (0.012) | – | 0.623 (0.028) | – | – | 0.882 (0.008) | – |
| Prescription stimulants | 0.749 (0.013) | 0.590 (0.038) | – | – | 0.834 (0.010) | – | – |
| Sedatives | 0.794 (0.009) | – | 0.448 (0.024) | – | – | 0.936 (0.006) | – |
| Heroin | 0.811 (0.014) | – | 0.174 (0.025) | – | – | 0.883 (0.014) | – |
| Cannabis | 0.842 (0.008) | – | – | 0.416 (0.012) | – | – | 0.913 (0.005) |
| Cocaine/crack | 0.937 (0.005) | -0.078 (0.020) | – | – | 0.936 (0.005) | – | – |
| Illicit stimulants | 0.799 (0.010) | 0.328 (0.029) | – | – | 0.848 (0.008) | – | – |
| Club drugs | 0.795 (0.011) | – | – | 0.443 (0.024) | – | – | 0.885 (0.008) |
| Hallucinogens | 0.906 (0.005) | – | – | 0.212 (0.015) | – | – | 0.948 (0.004) |
| Inhalants | 0.798 (0.012) | – | – | 0.176 (0.027) | – | – | 0.832 (0.010) |
| Factor correlation (95% CI) | |||||||
| Uppers | – | – | – | – | – | .83 (0.81-0.85) | .95 (0.94-0.97) |
| Downers | – | – | – | – | – | – | .81 (0.80-0.83) |
Note. Bold font indicates significant factor loading/correlation, p<.001.