Table 2.
Synopsis of Confirmatory Factor Models Informing the Structure of ADHD Symptoms at Each Assessment
| Age | Factors | χ2 | df | CFI | RMSEA | Comparison of Factors | Δχ2 | Δdf | Δp |
|---|---|---|---|---|---|---|---|---|---|
| 3 years | 1 | 510.2 | 135 | 0.97 | 0.05 | 1 vs. 2 | 1.0 | 1 | 0.3173 |
| 2 | 511.7 | 134 | 0.97 | 0.05 | 2 vs. 3 | 23.8 | 2 | < .0001 | |
| 3 | 492.6 | 132 | 0.97 | 0.05 | 1 vs. 3 | 24.1 | 3 | < .0001 | |
|
| |||||||||
| 4 years | 1 | 351.3 | 135 | 0.98 | 0.04 | 1 vs. 2 | 2.1 | 1 | 0.1485 |
| 2 | 351.4 | 134 | 0.98 | 0.04 | 2 vs. 3 | 17.4 | 2 | 0.0002 | |
| 3 | 335.3 | 132 | 0.96 | 0.04 | 1 vs. 3 | 19.2 | 3 | 0.0003 | |
|
| |||||||||
| 5 years | 1 | 319.9 | 135 | 0.99 | 0.04 | 1 vs. 2 | 3.3 | 1 | 0.0705 |
| 2 | 319.0 | 134 | 0.99 | 0.04 | 2 vs. 3 | 20.6 | 2 | < .0001 | |
| 3 | 297.9 | 132 | 0.99 | 0.03 | 1 vs. 3 | 21.3 | 3 | 0.0001 | |
Note. All tests of perfect fit were significant at p < .0001; the columns indicating changes in chi-square (Δχ2), degrees of freedom (Δdf), and probability (Δp) refer to tests between models that imposed a different number of factors (e.g., the last four columns of the first row of the table provide a formal comparison of whether the 2-factor model provides a statistically significant improvement in fit relative to the 1-factor model for the age 3 data).