Table 1

Characteristics of participants by dementia status

No dementia (n=636)Dementia (n=110)p Value
Mean (SD) age (y)72.0 (5.3)77.6 (6.7)<0.001
Sex (% women)56.074.5<0.001
APOE e4 genotype (%)14.531.0<0.001
Early life environment
    Mean (SD) birth order2.5 (1.7)2.5 (1.6)0.8
    Mean (SD) number of siblings5.0 (2.1)4.6 (1.8)0.07
    Parental manual occupation (%)92.795.40.3
    Rural residence before age 20 (%)83.589.10.1
    Any formal education (%)56.617.8<0.001
Reproductive history in women (n=438)
    Mean (SD) age at menarche16.5 (1.7)17.8 (1.3)<0.001
    Mean (SD) number of children5.1 (2.1)5.0 (2.2)0.6
    Mean (SD) age at first child birth21.7 (3.4)21.0 (2.4)0.1
    Mean (SD) age at menopause49.6 (4.5)48.2 (5.1)0.022