Table 2.
Raw unadjusted mean values on neuropsychological measures and compound Z-scores in patients with COPD and controls
| Outcome measure | COPD patients (n=90) |
Controls (n=90) |
P-value | Adjusted P-valuea |
|---|---|---|---|---|
| Global cognitive functioning | ||||
| MMSE, mean (SD)b | 27.4 (2.3) | 28.1 (1.6) | 0.017 | 0.016 |
| Global cognitive impairment (MMSE ≤24), n (%) | 7 (7.8) | 2 (2.2) | 0.084 | 0.243 |
| Domain-specific cognition | ||||
| Psychomotor speed (compound Z-score), mean (SD) | −0.5 (1.1) | 0.3 (0.7) | <0.001 | <0.001 |
| SCWT card I, mean (SD)b | 19.1 (5.6) | 17.0 (2.6) | 0.003 | 0.010 |
| CST-A, mean (SD) | 28.1 (15.8) | 21.2 (5.6) | <0.001 | <0.001 |
| LDST 60 second written, mean (SD) | 25.2 (7.2) | 31.7 (5.7) | <0.001 | <0.001 |
| LDST 60 second oral, mean (SD) | 31.1 (7.5) | 37.1 (6.5) | <0.001 | <0.001 |
| Planning (compound Z-score), mean (SD) | −0.3 (0.8) | 0.3 (0.6) | <0.001 | <0.001 |
| BADS key search, mean (SD) | 2.2 (1.5) | 3.1 (1.2) | <0.001 | 0.002 |
| BADS zoo map, mean (SD)b | 2.2 (0.8) | 2.7 (0.7) | <0.001 | <0.001 |
| Working memory (compound Z-score), mean (SD) | −0.6 (0.8) | −0.2 (0.8) | 0.004 | 0.035 |
| VVLT trial 1, mean (SD) | 4.4 (1.9) | 5.5 (2.1) | <0.001 | 0.001 |
| DS backward, mean (SD) | 3.0 (1.1) | 3.1 (1.2) | 0.556 | 0.961 |
| Verbal memory (compound Z-score), mean (SD) | −0.5 (1.1) | 0.0 (1.0) | 0.001 | 0.002 |
| VVLT total recall 1–5, mean (SD) | 40.2 (10.8) | 47.3 (10.2) | <0.001 | <0.001 |
| VVLT delayed recall, mean (SD) | 7.3 (3.5) | 9.1 (3.2) | 0.001 | 0.002 |
| VVLT retention max, mean (SD)b | 0.6 (0.3) | 0.7 (0.2) | 0.020 | 0.030 |
| Cognitive flexibility (compound Z-score), mean (SD) | −1.2 (1.6) | −0.0 (0.8) | <0.001 | <0.001 |
| SCWT card III, mean (SD)b | 60.9 (26.7) | 43.0 (13.0) | <0.001 | <0.001 |
| CST-C, mean (SD) | 51.1 (26.3) | 35.3 (11.6) | <0.001 | <0.001 |
| General cognitive impairment (2 out of 6 subtest | 51 (56.7) | 12 (13.3) | <0.001 | <0.001 |
| Z-scores −1 SD), n (%) | ||||
| Cognitive complaints | ||||
| CFQ absentmindedness, mean (SD) | 8.2 (5.4) | 7.1 (3.6) | 0.112 | 0.619 |
| CFQ social interactions, mean (SD) | 5.7 (3.3) | 4.9 (2.2) | 0.042 | 0.855 |
| CFQ names and words, mean (SD) | 5.7 (2.6) | 4.9 (2.0) | 0.021 | 0.081 |
| CFQ orientation, mean (SD) | 2.7 (2.6) | 2.3 (1.7) | 0.352 | 0.638 |
| CFQ total score, mean (SD) | 31.8 (17.3) | 27.3 (11.0) | 0.038 | 0.987 |
Notes:
a
Adjusted for myocardial infarction, peripheral vascular disease, hemiplegia, clinically relevant symptoms of depression, and clinically relevant symptoms of anxiety;
b
nonparametric statistical tests have been used because of skewed data.
Abbreviations: BADS, Behavioral Assessment of the Dysexecutive Syndrome; CFQ, Cognitive Failure Questionnaire; CST-A, Concept Shifting Test part A; CST-C, Concept Shifting Test part C; DS, Digit Span; LDST, Letter Digit Substitution Test; MMSE, Mini-Mental State Examination; SCWT, Stroop Color-Word Test; SD, standard deviation; VVLT, Visual Verbal Learning Test.