Table 1.

Characteristics of data/sample used from NACC for data analyses (predementia, AD dementia, and AD dementia community dwelling)

Item	Predementia (MCI due to AD)* n = 3553	AD Dementia† n = 4423	AD dementia Community‡ n = 4839
Age, mean (SD)	76 (7.2)	77 (7.4)	76 (7.3)
Female gender, n (%)	1816 (51)	2336 (53)	2527 (52)
Education (years), mean (SD)	16 (3.3)	15 (6.6)	14 (3.7)
Married, n (%)	2299 (65)	3058 (69)	3402 (70)
Living alone, n (%)	968 (27)	613 (14)	691 (14)
Diagnosed (MCI*/AD dementia†) at entry to NACC, n (%)	1905 (54)	3593 (81)	3871 (80)
Etiology:
AD primary, n (%)	3338 (94)	4258 (96)	4561 (94)
AD contributing, n (%)	215 (6)	165 (4)	278 (6)

Abbreviations: NACC, National Alzheimer’s Coordinating Center (USA); AD, Alzheimer’s disease; MCI, mild cognitive impairment.

^*Mild cognitive impairment due to Alzheimer’s disease.

^†Alzheimer’s disease dementia.

^‡Community dwelling with data between baseline and follow-up, selection criteria less stringent than data used for transitions between AD dementia states.