Table 3.
Baseline characteristics by cognitive state.
| Characteristic, n (%) | Normal cognition (n=7,612) | MCI due to AD (n=3,370) |
Mild AD dementia (n = 3,775) |
Mod. AD dementia (n = 681) | Severe AD dementia (n = 292) | Non-AD CI (n = 2,373) |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Demographics | |||||||||||||||||
| Age in years | |||||||||||||||||
| 65–74 | 3,953 | (51.9%) | 1,371 | (40.7%) | *** | 1,352 | (35.8%) | *** | 197 | (28.9%) | *** | 89 | (30.5%) | *** | 1,421 | (59.9%) | *** |
| 75–84 | 2,709 | (35.6%) | 1,560 | (46.3%) | *** | 1,855 | (49.1%) | *** | 318 | (46.7%) | *** | 136 | (46.6%) | ** | 804 | (33.9%) | |
| 85–94 | 910 | (12.0%) | 417 | (12.4%) | 545 | (14.4%) | ** | 158 | (23.2%) | *** | 61 | (20.9%) | *** | 145 | (6.1%) | *** | |
| 95+ | 40 | (0.5%) | 22 | (0.7%) | 23 | (0.6%) | 8 | (1.2%) | * | 6 | (2.1%) | ** | 3 | (0.1%) | ** | ||
| Female | 4,962 | (65.2%) | 1,684 | (50.0%) | *** | 2,001 | (53.0%) | *** | 418 | (61.4%) | * | 183 | (62.7%) | 1,088 | (45.9%) | *** | |
| Race | |||||||||||||||||
| White | 6,173 | (81.1%) | 2,805 | (83.2%) | ** | 3,085 | (81.7%) | 493 | (72.4%) | *** | 231 | (79.1%) | 1,926 | (81.2%) | |||
| Black | 1,038 | (13.6%) | 351 | (10.4%) | *** | 416 | (11.0%) | *** | 114 | (16.7%) | * | 34 | (11.6%) | 268 | (11.3%) | ** | |
| Other/unknown | 401 | (5.3%) | 214 | (6.4%) | * | 274 | (7.3%) | *** | 74 | (10.9%) | *** | 27 | (9.3%) | ** | 179 | (7.5%) | *** |
| Hispanic | 394 | (5.2%) | 215 | (6.4%) | * | 292 | (7.7%) | *** | 110 | (16.2%) | *** | 49 | (16.8%) | *** | 191 | (8.1%) | *** |
| Education level | |||||||||||||||||
| High school or less | 1,523 | (20.0%) | 853 | (25.3%) | *** | 1,416 | (37.5%) | *** | 323 | (47.4%) | *** | 133 | (45.6%) | *** | 707 | (29.8%) | *** |
| College | 3,220 | (42.3%) | 1,376 | (40.8%) | 1,409 | (37.3%) | *** | 217 | (31.9%) | *** | 95 | (32.5%) | ** | 956 | (40.3%) | ||
| Graduate school | 2,837 | (37.3%) | 1,135 | (33.7%) | ** | 933 | (24.7%) | *** | 135 | (19.8%) | *** | 57 | (19.5%) | *** | 696 | (29.3%) | *** |
| Unknown | 32 | (0.4%) | 6 | (0.2%) | * | 17 | (0.5%) | 6 | (0.9%) | 7 | (2.4%) | *** | 14 | (0.6%) | |||
| Marital status | |||||||||||||||||
| Married | 4,359 | (57.3%) | 2,223 | (66.0%) | *** | 2,552 | (67.6%) | *** | 368 | (54.0%) | 169 | (57.9%) | 1,656 | (69.8%) | *** | ||
| Widowed/divorced/separated | 2,773 | (36.4%) | 980 | (29.1%) | *** | 1,113 | (29.5%) | *** | 285 | (41.9%) | **> | 111 | (38.0%) | 614 | (25.9%) | *** | |
| Never married | 411 | (5.4%) | 140 | (4.2%) | ** | 99 | (2.6%) | *** | 19 | (2.8%) | **> | 10 | (3.4%) | 79 | (3.3%) | *** | |
| Other/unknown | 69 | (0.9%) | 27 | (0.8%) | 11 | (0.3%) | ** | 9 | (1.3%) | 2 | (0.7%) | 24 | (1.0%) | ||||
| Living situation | |||||||||||||||||
| Lives alone | 2,747 | (36.1%) | 895 | (26.6%) | *** | 653 | (17.3%) | *** | 72 | (10.6%) | *** | 4 | (1.4%) | *** | 485 | (20.4%) | *** |
| Able to live independently | 7,404 | (97.3%) | 2,570 | (76.3%) | *** | 938 | (24.9%) | *** | 13 | (1.9%) | *** | 1 | (0.3%) | *** | 1,329 | (56.0%) | *** |
| Residence | |||||||||||||||||
| Single family residence | 6,639 | (87.2%) | 2,926 | (86.8%) | 3,315 | (87.8%) | 562 | (82.5%) | ** | 160 | (54.8%) | *** | 2,067 | (87.1%) | |||
| Retirement community | 737 | (9.7%) | 233 | (6.9%) | *** | 219 | (5.8%) | *** | 25 | (3.7%) | *** | 2 | (0.7%) | *** | 112 | (4.7%) | *** |
| Assisted living/boarding home | 37 | (0.5%) | 53 | (1.6%) | *** | 138 | (3.7%) | *** | 56 | (8.2%) | *** | 29 | (9.9%) | *** | 68 | (2.9%) | *** |
| Skilled nursing facility/nursing home | 3 | (0.0%) | 1 | (0.0%) | 21 | (0.6%) | *** | 21 | (3.1%) | *** | 94 | (32.2%) | *** | 49 | (2.1%) | *** | |
| Other/unknown | 196 | (2.6%) | 157 | (4.7%) | *** | 82 | (2.2%) | 17 | (2.5%) | 7 | (2.4%) | 77 | (3.2%) | ||||
| Health history | |||||||||||||||||
| First-degree family member with dementia | 3,846 | (50.5%) | 1,822 | (54.1%) | ** | 2,146 | (56.9%) | *** | 370 | (54.3%) | 180 | (61.6%) | ** | 1,120 | (47.2%) | ** | |
| Congestive heart failure | 129 | (1.7%) | 60 | (1.8%) | 71 | (1.9%) | 21 | (3.1%) | 7 | (2.4%) | 40 | (1.7%) | |||||
| Cerebrovascular disease | 1,198 | (15.7%) | 580 | (17.2%) | 633 | (16.8%) | 120 | (17.6%) | 36 | (12.3%) | 414 | (17.5%) | * | ||||
| Depression | 1,183 | (15.5%) | 1,007 | (29.9%) | 1,397 | (37.0%) | *** | 273 | (40.1%) | *** | 114 | (39.0%) | *** | 939 | (39.6%) | *** | |
| Diabetes | 846 | (11.1%) | 436 | (12.9%) | ** | 458 | (12.1%) | 116 | (17.0%) | *** | 36 | (12.3%) | 354 | (14.9%) | *** | ||
| Hypercholesterolemia | 3,619 | (47.5%) | 1,790 | (53.1%) | 1,922 | (50.9%) | 324 | (47.6%) | 92 | (31.5%) | *** | 1,234 | (52.0%) | ||||
| Hypertension | 4,661 | (61.2%) | 2,225 | (66.0%) | *** | 2,427 | (64.3%) | ** | 429 | (63.0%) | 137 | (46.9%) | *** | 1,499 | (63.2%) | ||
| Incontinence | 912 | (12.0%) | 495 | (14.7%) | *** | 639 | (16.9%) | *** | 219 | (32.2%) | *** | 210 | (71.9%) | *** | 527 | (22.2%) | *** |
| Ischemic attack | 107 | (1.4%) | 57 | (1.7%) | 88 | (2.3%) | 15 | (2.2%) | 8 | (2.7%) | 54 | (2.3%) | |||||
| Parkinson’s disease | 86 | (1.1%) | 9 | (0.3%) | *** | 32 | (0.9%) | 4 | (0.6%) | 5 | (1.7%) | 230 | (9.7%) | *** | |||
| Psychiatric disorders | 187 | (2.5%) | 144 | (4.3%) | *** | 140 | (3.7%) | ** | 30 | (4.4%) | ** | 10 | (3.4%) | 133 | (5.6%) | *** | |
| Seizures | 27 | (0.4%) | 20 | (0.6%) | 27 | (0.7%) | ** | 8 | (1.2%) | ** | 14 | (4.8%) | *** | 28 | (1.2%) | *** | |
| Smoking | 280 | (3.7%) | 108 | (3.2%) | 133 | (3.5%) | 30 | (4.4%) | 3 | (1.0%) | * | 98 | (4.1%) | ||||
| Stroke | 171 | (2.3%) | 126 | (3.7%) | *** | 187 | (5.0%) | *** | 49 | (7.2%) | *** | 21 | (7.2%) | *** | 155 | (6.5%) | *** |
| Thyroid disease | 1,327 | (17.4%) | 529 | (15.7%) | * | 526 | (13.9%) | *** | 124 | (18.2%) | 41 | (14.0%) | 340 | (14.3%) | ** | ||
| Behavioral disturbances | |||||||||||||||||
| Agitation | 371 | (4.9%) | 593 | (17.6%) | *** | 1,232 | (32.6%) | *** | 342 | (50.2%) | *** | 183 | (62.7%) | *** | 652 | (27.5%) | *** |
| Irritability | 762 | (10.0%) | 1,044 | (31.0%) | *** | 1,646 | (43.6%) | *** | 374 | (54.9%) | *** | 160 | (54.8%) | *** | 903 | (38.1%) | *** |
| Nighttime behaviors | 653 | (8.6%) | 658 | (19.5%) | *** | 963 | (25.5%) | *** | 219 | (32.2%) | *** | 94 | (32.2%) | *** | 729 | (30.7%) | *** |
| Drug use | |||||||||||||||||
| Anxiolytic, sedative, or hypnotic agent | 735 | (9.7%) | 344 | (10.2%) | 304 | (8.1%) | ** | 55 | (8.1%) | 50 | (17.1%) | *** | 366 | (15.4%) | *** | ||
| Antidepressant | 1,117 | (14.7%) | 824 | (24.5%) | *** | 1,263 | (33.5%) | *** | 269 | (39.5%) | *** | 145 | (49.7%) | *** | 882 | (37.2%) | *** |
| Medication for AD symptoms | 103 | (1.4%) | 855 | (25.4%) | *** | 2,551 | (67.6%) | *** | 524 | (77.0%) | *** | 197 | (67.5%) | *** | 694 | (29.3%) | *** |
| Antiparkinson agent | 193 | (2.5%) | 70 | (2.1%) | 84 | (2.2%) | 7 | (1.0%) | * | 9 | (3.1%) | 321 | (13.5%) | *** | |||
| Antipsychotic agent | 35 | (0.5%) | 40 | (1.2%) | *** | 161 | (4.3%) | *** | 95 | (14.0%) | *** | 110 | (37.7%) | *** | 179 | (7.5%) | *** |
| Number ofAPOE e4 alleles | |||||||||||||||||
| Zero | 4,413 | (58.0%) | 1,475 | (43.8%) | *** | 1,219 | (32.3%) | *** | 190 | (27.9%) | *** | 79 | (27.1%) | *** | 1,138 | (48.0%) | *** |
| One | 1,596 | (21.0%) | 1,017 | (30.2%) | *** | 1,326 | (35.1%) | *** | 222 | (32.6%) | *** | 89 | (30.5%) | *** | 508 | (21.4%) | |
| Two | 123 | (1.6%) | 186 | (5.5%) | *** | 403 | (10.7%) | *** | 55 | (8.1%) | *** | 24 | (8.2%) | *** | 70 | (3.0%) | *** |
| Unknown | 1,480 | (19.4%) | 692 | (20.5%) | 827 | (21.9%) | ** | 214 | (31.4%) | *** | 100 | (34.3%) | *** | 657 | (27.7%) | *** | |
*=p<0.05; **=p<0.01; ***=p<0.0001; all comparisons relative to normal cognition
Notes:
[1] Baseline characteristics assessed at the first visit when age 65 or older. Includes all patients with ≥2 visits while age 65 or older.
[2] Normal cognition defined as a diagnosis of normal cognition (i.e., absence of impairment and dementia).
[3] MCI due to AD defined as a diagnosis of non-dementia cognitive impairment and identification of AD as the cause or a primary etiologic
diagnosis of AD at any time.
[4] AD dementia defined as a diagnosis of dementia and a primary etiologic diagnosis of AD at any time. Severity determined by global CDR
score: <2 for mild, 2 for moderate, and 3 for severe.
[5] Non-AD CI defined as a diagnosis of cognitive impairment or dementia and no primary etiologic diagnosis of AD at any time.
[6] Statistical significance calculated relative to normal cognition using Fisher’s exact test for categorical variables.
AD, Alzheimer’s disease; APOE, apolipoprotein E; CI, cognitive impairment; MCI, mild cognitive impairment.