ORs for abnormal SDQ score (17+) | n (%) abnormal SDQ | Unadjusted OR (95% CI) | p Value | A priori adjusted* OR (95% CI) | p Value | Fully adjusted OR (95% CI) | p Value |
---|---|---|---|---|---|---|---|
Any breast feeding | |||||||
Term children (n=9525) | |||||||
Never breast fed (n=3292) | 530 (16.1) | 1 | 1 | 1 | |||
Breast fed for: <2.0 months (n=2580) | 324 (12.6) | 0.83 (0.68 to 1.00) | 0.05 | 1.02 (0.84 to 1.26) | 0.8 | 1.00 (0.82 to 1.22)† | 0.9 |
2.0–3.9 months (n=912) | 96 (10.5) | 0.64 (0.48 to 0.86) | 0.003 | 0.95 (0.70 to 1.27) | 0.7 | 0.93 (0.69 to 1.26)† | 0.6 |
≥4.0 months (n=2741) | 179 (6.5) | 0.36 (0.30 to 0.44) | <0.001 | 0.67 (0.54 to 0.83) | <0.001 | 0.67 (0.54 to 0.83)† | <0.001 |
Preterm children (n=512) | |||||||
Never breast fed (n=177) | 31 (17.5) | 1 | 1 | 1 | |||
Breast fed for: ≤2.9 months (n=202) | 35 (17.3) | 0.65 (0.36 to 1.17) | 0.1 | 0.69 (0.36 to 1.33) | 0.3 | 0.65 (0.33 to 1.29)‡ | 0.2 |
≥3.0 months (n=133) | 12 (9.0) | 0.34 (0.16 to 0.70) | 0.004 | 0.93 (0.41 to 2.11) | 0.9 | 1.02 (0.44 to 2.37)‡ | 0.9 |
Exclusive breast feeding | |||||||
Term children (n=9525) | |||||||
Never breast fed (n=3292) | 530 (16.1) | 1 | 1 | 1 | |||
Exclusively breast fed for: <2.0 months (n=3360) | 398 (11.9) | 0.75 (0.62 to 0.90) | 0.002 | 1.00 (0.83 to 1.20) | 0.9 | 0.97 (0.81 to 1.16)† | 0.7 |
2.0–3.9 months (n=1465) | 117 (8.0) | 0.49 (0.39 to 0.62) | <0.001 | 0.82 (0.65 to 1.06) | 0.1 | 0.83 (0.64 to 1.06)† | 0.1 |
≥4.0 months (n=1408) | 84 (8.0) | 0.30 (0.23 to 0.41) | <0.001 | 0.61 (0.45 to 0.83) | 0.002 | 0.61 (0.45 to 0.83)† | 0.002 |
Preterm children (n=512) | |||||||
Never breast fed (n=177) | 31 (17.5) | 1 | 1 | 1 | |||
Exclusively breast fed for: ≤2.9 months (n=249) | 38 (15.3) | 0.56 (0.31 to 0.99) | 0.048 | 0.73 (0.37 to 1.41) | 0.3 | 0.66 (0.34 to 1.29)‡ | 0.3 |
≥3.0 months (n=86) | 9 (10.5) | 0.39 (0.18 to 0.85) | 0.018 | 1.14 (0.44 to 2.91) | 0.8 | 1.20 (0.45 to 3.22)‡ | 0.7 |
↵* Adjusted for mother's education (categories: NVQ 4–5 or equivalent, NVQ 3 or equivalent, NVQ 1–2 or equivalent, other), household SEP (managerial/professional, intermediate, routine/manual, never worked/unemployed), Malaise inventory scale (quintiles), Kessler scale (quintiles), mother's age (categories: 20–24, 25–29, 30–34, 35+), mother's smoking during pregnancy: (yes vs no), mother's relationship status (single parent vs not single parent), baby admitted to a neonatal unit (yes vs no).
↵† Adjusted for a priori confounders + Condon mother–baby attachment scale (quintiles) and birth order (first born vs not first born).
↵‡ Adjusted for a priori confounders + Condon mother–baby attachment scale (quintiles), type of childcare (formal informal, none), age started childcare (months), birth order (first born vs not first born), mother's alcohol use during pregnancy (never, 1–2 times/month, 1–4 times/week, 5+ times/week).
NVQ, National Vocational Qualification; SDQ, Strengths and Difficulties Questionnaire.