Table 3 Demographic, clinical and health variables by subgroup
NP normal/ CDR normal (n = 1451) Subgroup 1NP normal/ CDR MCI (n = 751) Subgroup 2NP MCI/CDR normal (n = 381) Subgroup 3NP MCI/CDR MCI (n = 480) Subgroup 4ANOVA F or χ2
Demographic variables
    Age78.0 (2.9)a78.7 (3.4)b78.7 (3.5)c79.6 (3.7)d31.62***
    Education (years)14.5 (2.8)a13.8 (2.8)b15.0 (3.1)c14.2 (3.3)a19.72***
    Gender (% female)690 (47.6%)a317 (42.2%)b172 (45.1%)a b237 (49.4%)aχ2 = 7.99*
Mental Status Tests
    ADAS5.6 (2.1)a6.7 (2.6)b7.1 (2.7)c8.4 (3.2)d159.73***
    3MSE95.0 (3.8)a93.1 (4.4)b92.2 (4.4)c89.7 (5.4)b189.28***
Premorbid functioning
    AMNART IQ118.3 (7.8)a115.7 (8.1)b116.1 (8.7)b113.7 (9.2)c41.29***
    Raven CPM29.7 (4.1)a28.9 (4.0)b26.5 (4.9)c25.7 (4.9)d129.29***
Clinical/health variables
    ApoE 4 allele (% carriers)†237 (20.0%)133 (22.3%)64 (21.3%)88 (24.2%)χ2 = 3.39
    CESD depression scale3.2 (3.1)a3.9 (3.7)b3.4 (3.4)a4.6 (4.1)c24.13***
    Sum endorsed health problems (out of 24)1.8 (1.6)a2.1 (1.8)b1.9 (1.8)a b2.1 (1.8)b7.31***
    Difficulty with IADLs (% yes)383 (26.4%)a239 (31.8%)b119 (31.3%)b177 (36.9%)bχ2 = 21.29***
    No of medications (Rx and OTC)7.1 (3.9)7.5 (4.2)7.0 (3.8)7.2 (3.9)0.54
    Mobility: difficulty walking half mile‡ (% yes)277 (19.2%)a167 (22.4%)a85 (22.7%)a143 (30.2%)bχ2 = 24.09***
    Deaths177 (12.2%)104 (13.8%)43 (11.3%)59 (12.3%)χ2 = 1.90
    Dropouts77 (5.3%)a47 (6.3%)a b26 (6.8%)a b44 (9.2%)bχ2 = 9.28*
    Dementia107 (7.4%)a129 (17.2%)b87 (22.8%)c199 (41.5%)dχ2 = 307.40***
  • Values are mean (SD) or n (%).

  • Means or proportions within a given row with different superscripts (a, b, c, d) are statistically different by Student–Neuman–Keuls procedure or modified Keppel–Bonferonni correction, respectively. Site included as covariates in omnibus ANOVAs.

  • *p<0.05, ***p<0.001.

  • †Reduced sample with ApoE genotyping, total n = 2445 (see methods).

  • ‡Self-report.

  • 3MSE, Modified Mini-Mental State Examination; ADAS, Alzheimer’s Disease Assessment Scale; AMNART, National Adult Reading Test-American version; ApoE, apolipoprotein E; CDR, Clinical Dementia Rating; CESD, Center for Epidemiological Studies Depression Scale; IADL, instrumental activities of daily living; MCI, mild cognitive impairment; NP, neuropsychological; OTC, over the counter; Raven CPM, Raven’s Coloured Progressive Matrices.