Skip to main content

Table 1 Demographic characteristics of the participants

From: Associations between breastfeeding and cognitive function in children from early childhood to school age: a prospective birth cohort study

Variables n (%)
Sex
 Male 893 (51.0)
 Female 859 (49.0)
Gestational age (days)
 < 259 (preterm) 52 (3.0)
 ≥ 259 (term) 1638 (93.5)
 Unknown 62 (3.5)
Birth weight (g)
 < 2500 49 (2.8)
 ≥ 2500 1647 (94.0)
 Unknown 56 (3.2)
Household income
 ≤ 2000 432 (24.7)
 > 2000 and ≤ 3000 532 (30.4)
 > 3000 and ≤ 4000 315 (18.0)
 > 4000 and ≤ 5000 193 (11.0)
 > 5000 111 (6.3)
 Unknown 169 (9.6)
Paternal educational level (years)
 ≤ 12 520 (29.7)
 > 12 and < 16 486 (27.7)
 ≥ 16 680 (38.8)
 Unknown 66 (3.8)
Maternal educational level (years)
 ≤ 12 454 (25.9)
 > 12 and < 16 362 (20.7)
 ≥ 16 809 (46.2)
 Unknown 127 (7.2)
Age at each assessment (months; mean; SD)
 T1 5.5 (1.2)
 T2 14.1 (1.0)
 T3 26.2 (1.3)
 T4 38.7 (1.4)
 T9 99.2 (1.4)