Table 1.
Demographics and clinical characteristics for cognitively normal (CDR = 0) participants at baseline
| All participants | Biomarker negative | Biomarker positive | P-valuea | ||||
|---|---|---|---|---|---|---|---|
| n | Mean (SD), or % | n | Mean (SD), or % | n | Mean (SD), or % | ||
| Age, mean (SD), years | 720 | 69.2 (9.2) | 560 | 67.9 (9.3) | 160 | 73.9 (6.8) | <0.0001 |
| Male sex, % | 302 | 41.9 | 231 | 41.2 | 71 | 44.4 | 0.4778 |
| Race, % | |||||||
| Non-Hispanic White | 621 | 86.3 | 470 | 83.9 | 151 | 94.4 | 0.0007 |
| African-American | 96 | 13.3 | 87 | 15.5 | 9 | 0.6 | 0.0012 |
| Asian | 2 | 0.3 | 2 | 0.4 | 0 | 0 | 0.4237 |
| More than one | 1 | 0.1 | 1 | 0.2 | 0 | 0 | 0.5687 |
| APOE ɛ4 carriers, % | 241 | 33.5 | 147 | 26.2 | 94 | 58.7 | <0.0001 |
| PRS, mean (SD) | 683 | −0.00355 (0.00729) | 531 | −0.00405 (0.00711) | 152 | −0.00181 (0.00762) | 0.0007 |
| Education, mean (SD), years | 720 | 16.0 (2.6) | 560 | 16.0 (2.5) | 160 | 16.0 (3.0) | 0.9890 |
| Baseline MMSE, mean (SD) | 720 | 29.1 (1.2) | 560 | 29.1 (1.1) | 160 | 29.0 (1.3) | 0.1954 |
| Final MMSE, mean (SD) | 718 | 28.7 (2.1) | 560 | 28.9 (1.5) | 158 | 27.7 (3.3) | <0.0001 |
| Interval from baseline assessment to final assessment, mean (SD) [median], years | 720 | 5.8 (3.4) [5.2] | 560 | 5.8 (3.5) [5.2] | 160 | 5.7 (3.1) [5.3] | 0.8415 |
| Interval from baseline biomarker to final assessment, mean (SD) [median], years | 720 | 5.6 (3.4) [5.1] | 560 | 5.6 (3.5) [5.1] | 160 | 5.6 (3.1) [5.1] | 0.8509 |
| Interval from baseline biomarker to study conclusionb or death, mean (SD) [median], years | 720 | 7.6 (3.7) [7.5] | 560 | 7.7 (3.8) [7.3] | 160 | 7.6 (3.4) [7.5] | 0.9424 |
| Mortality, % | 82 | 11.4 | 54 | 9.6 | 28 | 17.5 | 0.0058 |
| Progression to CDR > 0, %c | 102 | 14.17 | 47 | 8.4 | 55 | 34.4 | <0.0001 |
| CDR at final assessment | |||||||
| 0 | 633 | 87.9 | 521 | 93.0 | 112 | 70.0 | <0.0001 |
| 0.5 | 60 | 8.3 | 31 | 5.6 | 29 | 18.1 | <0.0001 |
| 1 | 24 | 3.3 | 8 | 1.4 | 16 | 10.0 | <0.0001 |
| 2 | 3 | 0.4 | 0 | 0 | 3 | 1.9 | 0.0012 |
| 3 | 0 | 0 | 0 | 0 | 0 | 0 | – |
| Progression to CDR > 0 by time interval of follow-up from initial biomarker to final assessment, % | |||||||
| 0–5 years | 39 | 11.0 | 17 | 6.1 | 22 | 28.6 | <0.0001 |
| 5–10 years | 45 | 16.2 | 20 | 9.5 | 25 | 36.8 | <0.0001 |
| 10–15 years | 17 | 19.5 | 9 | 12.5 | 8 | 53.3 | 0.0003 |
| 15–20 years | 1 | 50.0 | 1 | 50.0 | 0 | – | – |
| Clinical diagnoses assigned at time of final assessment for progressors (CDR > 0), % | |||||||
| AD dementiad | 70 | 68.6 | 26 | 55.3 | 44 | 80.0 | 0.0073 |
| Parkinson's disease dementia | 2 | 1.0 | 0 | 0 | 2 | 3.6 | 0.1868 |
| DLB | 1 | 1.0 | 1 | 2.1 | 0 | 0 | 0.2757 |
| Vascular dementia | 3 | 3.0 | 2 | 4.2 | 1 | 1.8 | 0.4654 |
| Non-AD dementia | 2 | 2.0 | 1 | 2.1 | 1 | 1.8 | 0.9124 |
| Uncertain dementiae | 24 | 23.5 | 17 | 36.1 | 7 | 12.7 | 0.0054 |
| No. defined by CSF biomarker, % | 117 | 16.3 | 81 | 14.4 | 36 | 22.5 | 0.0151 |
| t-tau, mean (SD), pg/ml | 117 | 234.8 (104.7) | 81 | 194.0 (57.0) | 36 | 326.8 (127.9) | <0.0001 |
| p-tau181 mean (SD), pg/ml | 117 | 21.5 (11.3) | 81 | 16.6 (4.6) | 36 | 32.6 (13.8) | <0.0001 |
| Aβ42 mean (SD), pg/ml | 117 | 1382.5 (623.6) | 81 | 1622.4 (578.3) | 36 | 842.8 (302.7) | <0.0001 |
| p-tau181/Aβ42, mean (SD) | 117 | 0.020 (0.018) | 81 | 0.011 (0.003) | 36 | 0.041 (0.020) | <0.0001 |
| No. defined by amyloid PET biomarker | 603 | 83.7 | 479 | 85.5 | 124 | 77.5 | 0.0151 |
| PIB SUVR, mean (SD) | 406 | 1.300 (0.610) | 318 | 1.021 (0.095) | 88 | 2.307 (0.624) | <0.0001 |
| AV45 SUVR, mean (SD) | 197 | 1.135 (0.459) | 161 | 0.951 (0.160) | 36 | 1.958 (0.457) | <0.0001 |
AD = Alzheimer’s disease; DLB = dementia with Lewy bodies.
P-values derived from tests comparing mean or % values between biomarker-negative and -positive subgroups. P-values < 0.05 are highlighted in bold.
Study conclusion date 19 April 2019.
Row highlighted in bold indicates main finding from this table.
AD dementia category includes the following diagnostic subgroups containing only a single participant: Biomarker negative = CDR 0.5 in memory only; Biomarker-positive = AD dementia with other contributing aetiology, AD dementia with depression contributing, AD dementia with disturbed social comportment, AD dementia with language dysfunction, CDR 0.5 in memory only.
Uncertain dementia category includes the following diagnostic subgroups: Uncertain dementia, Uncertain—possible non-AD dementia, Uncertain—questionable impairment.