Table 2.
Linear mixed models of neurocognitive change over time by treatment group and index
| Index Score Change | Beta | 95% CI | P |
|---|---|---|---|
| VCI Change | |||
| Slope: proton CSI | −0.3 | −1.8, 1.1 | 0.665 |
| Slope: proton focal | 0.6 | −0.6, 1.9 | 0.298 |
| Slope: surgery only | 0.7 | −0.4, 1.8 | 0.211 |
| Slope difference: proton CSI vs proton focal | −1.0 | −2.9, 0.9 | 0.316 |
| Slope difference: proton CSI vs surgery only | −1.0 | −2.8, 0.8 | 0.274 |
| Slope difference: proton focal vs surgery only | 0.0 | −1.7, 1.6 | 0.963 |
| PRI Change | |||
| Slope: proton CSI | 0.0 | −2.0, 2.0 | 0.998 |
| Slope: proton focal | 1.1 | −0.6, 2.7 | 0.192 |
| Slope: surgery only | 0.7 | −0.8, 2.1 | 0.366 |
| Slope difference: proton CSI vs proton focal | −1.1 | −3.6, 1.5 | 0.399 |
| Slope difference: proton CSI vs surgery only | −0.7 | −3.1, 1.8 | 0.591 |
| Slope difference: proton focal vs surgery only | 0.4 | −1.8, 2.6 | 0.699 |
| WMI Change | |||
| Slope: proton CSI | −1.8 | −3.6, −0.1 | 0.036* |
| Slope: proton focal | −0.4 | −1.9, 1.0 | 0.574 |
| Slope: surgery only | −0.4 | −1.7, 0.9 | 0.567 |
| Slope difference: proton CSI vs proton focal | −1.4 | −3.7, 0.8 | 0.205 |
| Slope difference: proton CSI vs surgery only | −1.5 | −3.6, 0.7 | 0.177 |
| Slope difference: proton focal vs surgery only | 0.0 | −2.0, 1.9 | 0.973 |
| PSI Change | |||
| Slope: proton CSI | −2.6 | −4.3,−0.9 | 0.004** |
| Slope: proton focal | 0.7 | −0.7, 2.2 | 0.315 |
| Slope: surgery only | 0.0 | −1.3, 1.3 | 0.993 |
| Slope difference: proton CSI vs proton focal | −3.3 | −5.6, −1.1 | 0.005** |
| Slope difference: proton CSI vs surgery only | −2.6 | −4.7, −0.5 | 0.019* |
| Slope difference: proton focal vs surgery only | 0.7 | −1.2, 2.7 | 0.450 |
| FSIQ Change | |||
| Slope: proton CSI | −1.7 | −3.1, −0.3 | 0.017* |
| Slope: proton focal | 1.2 | 0.0, 2.4 | 0.054 |
| Slope: surgery only | 0.4 | −0.7, 1.4 | 0.494 |
| Slope difference: proton CSI vs proton focal | −2.9 | −4.7, −1.1 | 0.003** |
| Slope difference: proton CSI vs surgery only | −2.1 | −3.8, −0.3 | 0.020* |
| Slope difference: proton focal vs surgery only | 0.8 | −0.8, 2.4 | 0.302 |
Note. Models were adjusted for clinical covariates significant on univariate comparisons: histology (glioma vs other), tumor location, total RT dose to tumor, posterior fossa syndrome, and shunt. Beta reported for each slope represents the increase/decrease in points per year on each index by treatment group. Slope difference compares slopes (ie, change in scores over time) between treatment groups on each index. *P < 0.05, **P < 0.01, ***P < 0.001.