Table 4.
Growth curve models of temporal course and rate of change in cognitive function
| Domain | Linear effect1 |
Quadratic effect2 |
||||||
|---|---|---|---|---|---|---|---|---|
| estimate | 95% CI | p3 | p4 | estimate | 95% CI | p3 | p4 | |
| Language | −0.05 (0.02) | −0.08, −0.02 | 0.004 | 0.004 | 0.02 (0.02) | −0.02, 0.06 | 0.318 | 0.347 |
| Visuospatial abilities | −0.05 (0.02) | −0.08, −0.02 | 0.002 | 0.002 | 0.06 (0.02) | 0.02, 0.10 | 0.007 | 0.014 |
| Memory | −0.03 (0.01) | −0.05, −0.01 | 0.012 | 0.013 | 0.04 (0.01) | 0.01, 0.06 | 0.013 | 0.023 |
| Attention-executive functions-psychomotor speed | −0.02 (0.01) | −0.04, −0.00 | 0.024 | 0.026 | 0.02 (0.01) | −0.01, 0.04 | 0.130 | 0.167 |
| Overall cognition | −0.04 (0.01) | −0.05, −0.02 | <0.001 | <0.001 | 0.03 (0.01) | 0.01, 0.05 | <0.001 | 0.001 |
Values in parentheses denote SE.
1
Linear effects were derived from models that tested only a ‘year’ term for time. Therefore, these effects represent annual rates of decline.
2
Quadratic effects were derived from models that simultaneously tested linear (i.e. year) and quadratic (i.e. year × year) terms for time. Because the quadratic terms are the effects of interest, test statistics for the linear terms are not reported in the table. The reported quadratic terms indicate the rate of deceleration in cognitive decline over time.
3
p from model that only adjusted for baseline performance.
4
p from model that adjusted for baseline performance and age.