Table 2. Effect of Training on Cognitive and Functional Outcomes From Baseline to Year 10.
| Intervention Groups | ||||
|---|---|---|---|---|
| Memory | Reasoning | Speed | Control Group | |
| Memory (possible range: 0 to 132, N=943) | ||||
|
| ||||
| Score at baseline, mean (±SD) | 82.1 (±25.7) | 79.5 (±26.3) | 79.1 (±25.5) | 79.8 (±27.3) |
|
| ||||
| Mean change from baseline to year 10 | −10.6 | −11.2 | −12.7 | −9.4 |
|
| ||||
| Effect size (99% CI)* | 0.06 (−0.14,0.27) | −0.11 (−0.31,0.10) | −0.05 (−0.25,0.15) | |
|
| ||||
| % at or above baseline level § | 35.9% | 28.6% | 31.0% | 31.0% |
|
| ||||
| Reasoning (possible range: 0 to 75, N=938) | ||||
|
| ||||
| Score at baseline, mean (±SD) | 31.8 (±11.7) | 29.6 (±12.3) | 28.9 (±12.0) | 30.2 (±12.8) |
|
| ||||
| Mean change from baseline to year 10 | −3.2 | −0.05 | −3.9 | −3.0 |
|
| ||||
| Effect size (99% CI)* | −0.02 (−0.17,0.12) | 0.23 (0.09,0.38) | −0.06 (−0.20,0.08) | |
|
| ||||
| % at or above baseline level § | 60.0% | 73.6% (p<.01) | 59.3% | 61.7% |
|
| ||||
| Speed of Processing (possible range: 0 to 1500, N=883) | ||||
| Score at baseline, mean (±SD) | 774.1 (±216.9) | 800.9 (±231.0) | 830.0 (±231.9) | 800.6 (±231.8) |
|
| ||||
| Mean change from baseline to year 10 | −144.4 | −126.2 | 24.3 | −123.3 |
|
| ||||
| Effect size (99% CI)* | −0.07 (−0.29,0.16) | 0.005 (−0.22,0.23) | 0.66 (0.43,0.88) | |
|
| ||||
| % at or above baseline level § | 47.2% | 48.5% | 70.7% (p<.01) | 47.8% |
|
| ||||
| IADL difficulty (possible range: 0 to 38**, N=1211) | ||||
|
| ||||
| Score at baseline, mean (±SD) | 1.0 (±1.8) | 1.2 (±2.0) | 1.1 (±2.0) | 0.9 (±2.1) |
|
| ||||
| Mean change from baseline to year 10 | −3.1 | −2.7 | −2.3 | −3.6 |
|
| ||||
| Effect size (99% CI)* | 0.48 (0.12,0.84) | 0.38 (0.02,0.74) | 0.36 (0.01,0.72) | |
|
| ||||
| % at or above baseline level § | 61.6% (p<.01) | 60.2% (p<.01) | 58.5% (p<.05) | 49.3% |
|
| ||||
| Everyday problem solving (possible range: 0 to 56, N=1104) | ||||
|
| ||||
| Score at baseline, mean (±SD) | 40.7 (±7.7) | 39.2 (±8.1) | 38.7 (±7.7) | 39.4 (±9.1) |
|
| ||||
| Mean change from baseline to year 10 | −6.1 | −5.6 | −6.0 | −5.7 |
|
| ||||
| Effect size (99% CI)* | 0.004 (−0.23,0.24) | −0.02 (−0.25,0.22) | 0.008 (−0.23,0.24) | |
|
| ||||
| % at or above baseline level § | 59.6% | 63.1% | 61.0% | 61.4% |
|
| ||||
| Everyday speed of processing (possible range: −3 to 100, N=938)+ | ||||
|
| ||||
| Score at baseline, mean (±SD) | 3.2 (±1.0) | 3.3 (±1.2) | 3.4 (±1.3) | 3.4 (±1.1) |
|
| ||||
| Mean change from baseline to year 10 | −1.5 | −1.4 | −1.5 | −1.4 |
|
| ||||
| Effect size (99% CI)* | 0.02 (−0.19,0.23) | −0.004 (−0.21,0.21) | −0.05 (−0.26,0.16) | |
|
| ||||
| % at or above baseline level § | 34.9% | 30.5% | 29.0% | 30.2% |
Abbreviations: CI, confidence interval; SD, standard deviation; IADL, instrumental activities of daily living.
*
Effect size defined as training improvement from baseline to year 10 minus control improvement from baseline to year 10 divided by the intrasubject SD of the composite score. Positive effect sizes indicate improvement.
**
Coded as 0=no difficulty; 1=some help needed or participant is slow or becomes tired’; 2=great difficulty
+
One component of this composite score is a standardized z score with a potential range of −∞to ∞.
§
Calculated as the percentage of participants in each group who were ≥0.66 SEM above baseline.