Table 2.
Demographic characteristics and performance on component neuropsychological measures (raw) and composites (z) at baseline by biomarker group. All participants are cognitively unimpaired at baseline. Statistics reported are of the form mean (standard deviation, SD) or n (%).
| A− (n=428) | A+ (n=186) | p-value | |
|---|---|---|---|
| Age, years | 72.47 (4.81) | 73.79 (5.03) | 0.0021 |
| Education, years | 14.86 (2.57) | 14.52 (2.66) | 0.1361 |
| Male sex | 233 (54.4%) | 102 (54.8%) | 0.9272 |
| APOE ε4 carrier | 89 (21.0%) | 88 (47.6%) | < 0.0012 |
| CDR global score | 0.0972 | ||
| 0 | 416 (97.7%) | 175 (95.1%) | |
| 0.5 | 10 (2.3%) | 9 (4.9%) | |
| PiB SUVr | 1.36 (0.07) | 1.87 (0.39) | < 0.0011 |
| Visit to PiB scan, years | 0.92 (0.89) | 1.07 (0.98) | 0.0621 |
| Number of MCSA visits | 6 (2) | 6 (2) | 0.4401 |
| Follow up, years | 7.23 (2.70) | 7.13 (3.02) | 0.6921 |
| Mayo-PACC, z-score | 0.000 (0.745) | −0.106 (0.631) | 0.0921 |
| PACC-R, z-score | 0.000 (0.676) | −0.080 (0.611) | 0.1661 |
| ADCS-PACC3, z-score | 0.000 (0.694) | −0.118 (0.661) | 0.0501 |
| Global-z | 0.062 (0.855) | −0.127 (0.813) | 0.0111 |
| MMSE from Kokmen STMS | 28.42 (1.15) | 28.32 (1.23) | 0.3401 |
| Kokmen STMS (original scale) | 35.32 (2.06) | 35.21 (2.16) | 0.5391 |
| AVLT Trials 1-5 Total | 41.63 (9.16) | 40.63 (8.57) | 0.2041 |
| AVLT Long delay recall | 7.85 (3.42) | 7.52 (3.23) | 0.2581 |
| AVLT Sum of Trials | 57.75 (14.68) | 56.13 (13.84) | 0.2041 |
| AVLT Recognition hits | 12.80 (2.25) | 12.77 (2.37) | 0.8831 |
| AVLT Recognition % correct | 89.57 (9.05) | 88.72 (11.52) | 0.3301 |
| WMS-R Logical Memory I total | 23.75 (6.62) | 23.44 (6.56) | 0.5881 |
| WMS-R Logical Memory II total | 18.96 (7.42) | 18.03 (7.02) | 0.1461 |
| WMS-R Visual Reproduction I | 31.02 (5.03) | 30.12 (4.74) | 0.0381 |
| WMS-R Visual Reproduction II | 23.66 (7.96) | 22.28 (7.94) | 0.0481 |
| TMT A total, seconds | 34.87 (11.16) | 36.89 (12.53) | 0.0481 |
| TMT B total, seconds | 87.61 (40.96) | 89.01 (31.91) | 0.6781 |
| WAIS-R Digit Symbol Coding | 46.96 (9.89) | 45.34 (9.44) | 0.0591 |
| Animal Fluency | 20.27 (5.00) | 19.40 (4.33) | 0.0401 |
| Fruit Fluency | 13.25 (3.69) | 12.95 (3.59) | 0.3581 |
| Vegetable Fluency | 12.45 (3.72) | 12.57 (3.45) | 0.7101 |
| Category Fluency total | 45.97 (9.96) | 44.92 (9.01) | 0.2201 |
| Boston Naming Test | 55.95 (3.42) | 55.33 (3.95) | 0.0491 |
| WAIS-R Picture Completion | 14.00 (2.80) | 13.62 (2.92) | 0.1311 |
| WAIS-R Block Design | 26.87 (8.35) | 24.92 (8.16) | 0.0071 |
Linear Model ANOVA
Pearson’s Chi-squared test
Approximation of the ADCS-PACC.
Note. Composites are defined in Table 1. ADCS: Alzheimer Disease Cooperative Study; AVLT: Rey Auditory Verbal Learning Test; MMSE from STMS: Mini Mental Status Examination calculated from the Kokmen Short Test of Mental Status; PACC: Preclinical Alzheimer’s cognitive composite; Recognition % Correct: (true positives + true negatives)/total; Sum of Trials: sum of Trials 1-5 total, short delay, and long delay; TMT = Trail Making Test; WMS-R: Wechsler Memory Scale-Revised; WAIS-R: Wechsler Adult Intelligence Scale-Revised.