Table 5.
Model-fitting statistics for the univariate ACE model, comparing a full ACE model against various constrained submodels
| Base model | Comparison model | Estimated parameters | -2LL | AIC | df | Change in -2LL | Change in df | p |
|---|---|---|---|---|---|---|---|---|
| ACE | 6 | 2,480.670 | 424.670 | 1028 | ||||
| ACE | AE | 5 | 2,489.763 | 431.763 | 1029 | 9.093 | 1 | 0.003 |
| ACE | CE | 5 | 2,505.025 | 447.025 | 1029 | 24.356 | 1 | <0.001 |
| ACE | E | 4 | 2,886.138 | 826.138 | 1030 | 405.469 | 2 | <0.001 |
A, additive genetic effects; C, shared environmental effects; E, non-shared environmental effects; -2LL, minus two log-likelihood; AIC, Akaike Information Criterion; df, degrees of freedom.
ACE represents the full model, while AE and CE are submodels that drop the C and A paths, respectively.
A lower AIC represents a better model fit. A significant p-value indicates a significantly worse model fit.