Table 3.
Hierarchical regression results for predicting apathy
| Predictor | B | SE | t | sig. | Δr2 |
|---|---|---|---|---|---|
| Step 1 | |||||
| Age | 0.05 | 0.00 | 0.02 | .98 | .00 |
| Gender | 1.33 | 0.02 | 0.23 | .82 | .00 |
| BDI- II, cog-affective subscore | 0.09 | 0.53 | 6.38 | .00 | .25 |
| log10 highest plasma RNA level | 0.00 | 0.17 | 2.05 | .04 | .03 |
| Nadir CD4 cell count | 0.00 | 0.06 | 0.73 | .47 | .00 |
| Disease duration (years) | 0.09 | 0.02 | 0.26 | .79 | .00 |
| Comorbid hepatitis C virus | 1.92 | 0.13 | 1.54 | .13 | .01 |
| Stroop color-word performance | 0.08 | −0.02 | −0.18 | .86 | .00 |
| CR composite score | 0.80 | −0.20 | −2.37 | .02 | .03 |
| Step 2 | |||||
| CR × log10 highest plasma RNA | −0.16 | 0.00 | −1.10 | .27 | .01 |
| CR × nadir CD4 cell count | 0.31 | 0.00 | 2.27 | .03 | .03 |
| CR × disease duration | 0.00 | 0.11 | −0.02 | .98 | .00 |
| CR × age | 0.29 | 0.05 | 1.03 | .31 | .01 |
Notes: CR = cognitive reserve; BDI-II = Beck Depression Inventory-II. Gender: 0 = men, 1 = women. Comorbid hepatitis C virus: 0 = no, 1 = yes. Δr2 = change in r2 for adding this predictor to the model last. Step 1: R2 = .43, F = 7.8, p < .001. Step 2: R2 = .48, F = 6.5, p < .001.