Table 2.
Effects of protocol type and consent method.
| Lower Risk | Higher Risk | ||||||
|---|---|---|---|---|---|---|---|
| Routine | Enhanced | Routine | Enhanced | Statistical Test with df | p | ||
| Normal comparison subjects | n=35 | n=34 | n=35 | n=30 | |||
| 5-item total | 9.0 (1.3) | 9.5 (0.9) | 9.2 (1.4) | 9.7 (0.6) | F(3, 129) = 2.22 | 0.090 | |
| MacCAT-CR | |||||||
| Understanding Trial 1 | 22.6 (2.6) | 22.4 (3.0) | 22.7 (4.0) | 21.3 (4.0) | F(3,130) = 1.05 | 0.374 | |
| Understanding Trial 2 | 25.3 (1.1) | 25.2 (1.1) | 24.9 (2.3) | 24.8 (2.2) | F(3,130) = 0.21 | 0.890 | |
| Appreciation | 5.2 (1.0) | 5.5 (0.8) | 5.1 (1.1) | 4.7 (1.1) | F(3,128) = 4.10 | 0.008a | |
| Reasoning | 7.3 (1.3) | 7.6 (0.7) | 7.5 (0.9) | 7.5 (0.8) | F(3,129) = 0.86 | 0.463 | |
| Expression of a Choice | 1.9 (0.2) | 1.9 (0.2) | 1.9 (0.3) | 2.0 (0.0) | χ2(3) = 1.97 | 0.579 | |
| Capable (% Yes) | 100.0% | 100.0% | 91.4% | 96.7% | χ2(3) = 5.91 | 0.116 | |
| Alzheimer’s disease | n=33 | n=26 | n=31 | n=24 | |||
| 5-item total | 5.4 (2.6) | 6.0 (2.1) | 5.9 (2.6) | 6.0 (3.0) | F(3,108) = 0.44 | 0.726 | |
| MacCAT-CR | |||||||
| Understanding Trial 1 | 11.5 (6.1) | 12.8 (6.3) | 11.9 (7.8) | 14.0 (7.0) | F(3,110) = 0.69 | 0.560 | |
| Understanding Trial 2 | 15.1 (6.9) | 17.8 (7.0) | 15.7 (7.7) | 16.8 (7.6) | F(3,110) = 0.75 | 0.523 | |
| Appreciation | 4.2 (1.3) | 4.2 (1.8) | 4.1 (1.7) | 4.2 (1.6) | F( 3,110) = 0.03 | 0.994 | |
| Reasoning | 5.6 (2.5) | 6.9 (1.5) | 6.3 (2.4) | 6.2 (2.5) | F(3,108) = 1.54 | 0.208 | |
| Expression of a Choice | 1.7 (0.6) | 1.8 (0.6) | 1.5 (0.8) | 1.7 (0.7) | χ2(3) = 2.11 | 0.550 | |
| Capable (% Yes) | 30.3% | 46.2% | 32.3% | 45.8% | χ2(3) = 2.63 | 0.453 | |
a
Higher Risk Enhanced Consent < Lower Risk Routine Consent and Lower Risk Enhanced Consent
Note: MMSE = Mini Mental State Examination; DRS = Mattis Dementia Rating Scale; MacCAT-CR = MacArthur Competence Assessment Tool for Clinical Research.