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. Author manuscript; available in PMC: 2019 Jan 1.
Published in final edited form as: Clin Gerontol. 2017 Nov 28;41(1):20–32. doi: 10.1080/07317115.2017.1373177

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.