Table 4.
Regression equations for predicting one year processing speed scores
| Cognitive scores | F(df) | R2 | SEesta | Cb | Variables in equationc |
|---|---|---|---|---|---|
| Same test | |||||
| TMT-A | 37.81 (2,124) | 0.38*** | 15.28 | -18.80 | + (baseline TMT-A *0.62) + (age*0.45) |
| TMT-B | 65.67 (2,124) | 0.51*** | 45.27 | -105.54 | + (baseline TMT-B *0.71) + (age*1.75) |
| SDMT | 132.35 (1,123) | 0.52*** | 8.15 | 4.10 | + (baseline SDMT*0.90) |
| Coding | 130.33 (2,124) | 0.68*** | 6.34 | 22.29 | + (baseline Coding*0.84) - (age*0.21) |
| Different test | |||||
| TMT-A | 31.44 (2,124) | 0.34*** | 15.79 | -11.56 | + (baseline TMT-B *0.17) + (age*0.47) |
| TMT-A | 67.71 (1,125) | 0.35*** | 15.55 | 92.38 | - (baseline SDMT *1.21) |
| TMT-A | 57.72 (1,125) | 0.32*** | 15.97 | 88.56 | - (baseline Coding *1.12) |
| TMT-B | 39.36 (2,124) | 0.39*** | 50.81 | -172.37 | + (baseline TMT-A*1.61) + (age*2.72) |
| TMT-B | 44.29 (2,124) | 0.42*** | 49.62 | 76.19 | - (baseline SDMT*3.20) + (age*2.08) |
| TMT-B | 40.88 (2,124) | 0.40*** | 50.43 | 51.00 | - (baseline Coding*2.89) + (age*2.24) |
| SDMT | 26.66 (2,122) | 0.30*** | 9.84 | 90.85 | - (baseline TMT-A*0.21) − (age*0.53) |
| SDMT | 31.61 (2,122) | 0.34*** | 9.57 | 84.04 | - (baseline TMT-B*0.08) − (age*0.44) |
| SDMT | 124.35 (1,123) | 0.50*** | 8.29 | 5.95 | + (baseline Coding*0.86) |
| Coding | 48.48 (2,124) | 0.44*** | 8.37 | 93.73 | - (baseline TMT-A*0.28) − (age*0.54) |
| Coding | 57.29 (2,124) | 0.48*** | 8.05 | 86.36 | - (baseline TMT-B*0.10) − (age*0.46) |
| Coding | 103.29 (2,124) | 0.63*** | 6.84 | 27.55 | + (baseline SDMT*0.80) − (age*0.25) |
Note. TMT-A = Trail Making Test Part A, TMT-B = Trail Making Test Part B, SDMT = Symbol Digit Modalities Test. For the R2, the following key denotes the significance of the final step within the regression model:
***
p<0.001,
**
p<0.01,
*
p<0.05.
a
Standard error of the estimate,
b
Constant,
c
Unstandardized beta weights for other variables in the equation. Age is years old at baseline visit. To calculate the Predicted One Year score, use the following formula: (Constant value for the cognitive variable) + (Other variables in equation as noted in the Table).