Table 1

Baseline Characteristics of Participants by Treatment Groupa
CharacteristicVitamin E
(n = 152)
Memantine (n = 155)Vitamin E + Memantine (n = 154)Placebo (n = 152)
Age, mean (SD) [range], y78.6 (7.2) [55-93]78.8 (7.2) [53-92]78.3 (7.0) [54-94]79.4 (7.0) [61-96]
Male sex, No. (%)146 (96)149 (96)150 (97)149 (98)
Race/ethnicity, No. (%)a
 White131 (86)132 (85)136 (88)131 (86)
 Black21 (14)21 (14)18 (12)20 (13)
 Other1 (1)2 (1)01 (1)
 Hispanic17 (11)15 (10)15 (10)19 (13)
Education, No. (%)
 <High school graduation41 (27)41 (26)26 (17)29 (19)
 High school graduation46 (30)48 (31)57 (37)56 (37)
 Some college27 (18)38 (25)37 (24)33 (22)
 College graduation or advanced degree38 (25)28 (18)34 (22)34 (22)
APOE ε4 status, No. (%)
 Noncarriers47 (49.0)48 (45.7)59 (53.2)55 (53.4)
 One ε4 allele39 (40.6)44 (41.9)44 (39.6)38 (36.9)
 Two ε4 alleles10 (10.4)13 (12.4)8 (7.2)10 (9.7)
Charlson Risk Index score, mean (SD)b2.4 (1.7)2.4 (1.6)2.4 (1.8)2.7 (1.8)
Comorbidity Disease Index domains, No. (%)c
 ≤164 (42)73 (47)75 (49)71 (47)
 239 (26)43 (28)40 (26)36 (24)
 ≥349 (32)39 (25)39 (25)45 (30)
AChEI, No. (%)d
 Donepezil104 (68)100 (65)100 (65)96 (63)
 Galantamine43 (28)47 (30)49 (32)55 (36)
 Rivastigmine5 (3)8 (5)4 (3)1 (1)
 Time from AChEI start to randomization
  ≤12 wk46 (31)36 (23)49 (32)37 (24)
  >12 wk105 (69)119 (77)104 (68)115 (76)
ADCS-ADL, mean (SD) [range]e56.6 (14.9) [13-78]57.3 (14.2) [11-78]56.4 (14.0) [15-78]56.8 (13.7) [8-78]
MMSE, mean (SD) [range]f21.3 (3.3) [12-26]20.8 (3.8) [12-26]21.3 (3.4) [12-26]20.8 (3.8) [12-26]
ADAS-cog score, mean (SD) [range]g18.5 (8.8) [5.0-51.0]19.5 (7.9) [2.3-50.0]18.0 (8.4) [4.0-56.0]19.1 (8.4) [3.0-46.3]
NPI score, median (range)]h7.5 (0-61)8.0 (0-95)8.0 (0-81)8.0 (0-62)
CAS time, median (range), hi2.7 (0-144)3.2 (0-49)3.2 (0-97)3.0 (0-59)
Dependence Scale level, No. (%)j
 05 (3)6 (4)8 (5)3 (2)
 18 (5)6 (4)8 (5)5 (3)
 285 (56)91 (59)80 (52)79 (52)
 331 (20)35 (23)31 (20)37 (24)
 44 (3)7 (5)10 (6)8 (5)
 519 (13)10 (6)17 (11)20 (13)
Abbreviations: AChEI; acetylcholinesterase inhibitor; ADAS-cog, Alzheimer Disease Assessment Scale–Cognitive Subscale; ADCS-ADL, Alzheimer's Disease Cooperative Study/Activities of Daily Living; APOE, apolipoprotein E; CAS, Caregiver Activity Survey; MMSE, Mini-Mental State Examination; NPI, Neuropsychiatric Inventory.

aRace and ethnicity were self-identified by participants; >1 race was indicated by 1 participant in the vitamin E only group.
bPredicts 10-year mortality based on 22 comorbid conditions, each assigned 1, 2, 3, or 6, depending on risk of dying associated with the condition.
cDomains include cardiac, respiratory, neurologic, musculoskeletal, general (mental or emotional problems and sleep or pain disorders), cancer, diabetes, and visual problems. The domain scores are totaled to create an overall comorbidity score (≤1, 2, or ≥3 domains).
dOne participant was not taking an AChEI at baseline, which represented a protocol violation. Data was missing for 1 participant's AChEI initiation date and 1 participant was not taking an AChEI at baseline.
eRange, 0-78; higher scores = better functioning.
fRange, 0-30; higher scores = better functioning.
gAssesses cognitive function in the areas of memory, language, and praxis functions; range, 0-70: higher scores = worse functioning.
hAssesses frequency and severity of psychological and behavioral problems in patients with dementia; range, 0-144: higher scores = more frequent and/or severe behavioral problems.
iMeasures caregiver time in caring for patients with dementia, summing total hours spent in a day on 6 caregiving tasks; range, 0-144 hours: higher scores = more time spent on caregiving.
jLevel of assistance needed by patients with AD on scale of 0-5.