Table 5.
Results for Longitudinal Latent Curve/Mixed Effects Models Applied to Longitudinal HRS/ADAMS Episodic Memory Data
| (a) Age | (b) + APOE4 | (c) + Educ | (d) + APOE4 × Educ | |
|---|---|---|---|---|
| Parameter Estimate (T-value) | ||||
| Fixed Effects | ||||
| α0=1 → f0 | 5.62 (35) | 5.70 (30) | 5.72 (32) | 5.72 (32) |
| β0= 1 → f1 | −0.59 (6.9) | −0.60 (6.1) | −0.59 (6.2) | −0.59 (6.2) |
| α1= APOE4→ f0 | =0 | −0.28 (0.8) | −0.33 (1.0) | −0.37 (1.1) |
| β1= APOE4→ f1 | =0 | +0.01 (0.8) | +0.19 (0.2) | +0.09 (0.5) |
| α2= Educ → f0 | =0 | =0 | 0.27 (7.1) | 0.31 (7.1) |
| β2= Educ → f1 | =0 | =0 | −0.05 (2.8) | −0.08 (3.8) |
| α3= GxE → f0 | =0 | =0 | =0 | −0.19 (2.3) |
| β3= GxE → f1 | =0 | =0 | =0 | +0.12 (2.9) |
| Random Effects | ||||
| Intercept σ02 | 3.66 (5.3) | 3.56 (5.3) | 2.75 (5.1) | 2.70 (4.9) |
| Slope σ12 | 0.68 (3.9) | 0.63 (3.9) | 0.59 (4.2) | 0.60 (4.2) |
| Covariance σ01 | −1.74 (3.6) | −1.74 (3.6) | −1.00 (3.8) | −1.00 (3.7) |
| Unique Variance Ψ2 | 1.94 (23) | 1.94 (23) | 1.94 (23) | 1.93 (23) |
| Model Fit Information | ||||
| Likelihood (L2) | −2242 | −2239 | −2236 | −2144 |
| ΔL2 | -- | +3 | +3 | +92 |
| Scale | 2.15 | 2.08 | 2.05 | 1.97 |
| # Parameters | 12 | 14 | 16 | 18 |
Age= (age in years – 60)/10; Educ = (# years education-12)/4; APOE4 is coded 0 if no ε4 alleles, and 1 if one or two ε4 alleles; ΔL2= change in likelihood relative to prior model