Table 3 Socio-demographic characteristics of the infants in the study population according to the duration of exclusive breastfeeding

From: Exclusive breastfeeding duration and infant infection

  Never BF EBF <2 months EBF 2–4 months EBF 4–6 months EBF 6+ months
  Group 1 N=5382 Group 2 N=5645 Group 3 N=2335 BF <6 months, had formula and/or solids before 6 months Group 4 N=533 BF 6+ months, had formula and solids before 6 months Group 5 N=556 BF 6+ months, had solids but no formula before 6 months Group 7 (pre-2001 WHO policy) N=1122 Group 8 (post-2001 WHO policy) N
Socio-demographic characteristics        
 Infant sex—female (%) 50.2 48.6 45.7 52.2 56.6 54.0 52.0
 Infant ethnicity—white (%) 93.2 83.9 87.2 84.8 86.8 83.9 73.3
 Mother’s age at delivery, mean (s.d.) 26.8 (6.3) 28.8 (5.6) 29.8 (5.0) 30.5 (5.0) 32.0 (4.3) 31.2 (4.9) 31.4 (5.5)
Mother’s education
 University degree or equivalent (%) 12.5 35.2 43.5 45.6 60.0 55.1 48.9
 A levels or equivalent (%) 13.0 14.6 16.6 15.2 12.3 14.3 10.3
 Lower than A levels (%) 52.3 40.0 34.5 32.3 22.2 25.8 30.5
 No formal qualifications (%) 22.2 10.6 5.4 6.9 5.4 4.8 10.2
Highest occupation of mother and father
 Professional/managerial (%) 24.4 46.9 57.2 58.2 68.7 67.0 60.6
 Intermediate (%) 20.5 20.5 18.9 18.8 17.2 16.0 22.6
 Routine and manual (%) 47.4 28.4 21.6 18.7 12.8 14.3 13.6
 Never worked (%) 7.8 4.2 2.3 4.4 1.4 2.7 3.2
Marital status—single (%) 24.1 11.8 9.3 8.9 19.0 4.6 6.3
Household income less than £10 400 p.a. (%) 32.8 18.3 12.8 13.0 9.1 10.8 13.2
Household crowdinga (%) 12.3 9.1 6.5 8.8 5.2 8.9 13.0
  1. Abbreviations: BF, breastfed; EBF, exclusively breastfed.
  2. aCrowding defined as <1 room per person (rooms/people <1).