The association between early formula and reduced risk of cow’s milk allergy during the first three year of life: a Japanese cohort study

Table 2 The association between periods of formula consumption and food allergies

a. All children for the analysis (n = 59,560)
	CMA
	At 6 m	At 12 m	At 18 m	At 24 m	At 36 m
Formula consumption	aRR (95% CI)	aRR (95% CI)	aRR (95% CI)	aRR (95% CI)	aRR (95% CI)
Very early (0–3 months old)	1.00 (0.65–1.51)	1.14 (0.94–1.36)	1.10 (0.92–1.30)	1.08 (0.86–1.35)	0.97 (0.73–1.27)
Early (3–6 months old)	0.01 (0.00–0.05)^a	0.19 (0.10–0.34)	0.23 (0.16–0.33)	0.41 (0.26–0.64)	0.47 (0.26–0.80)
Late (6–12 months old)	–	0.01 (0.00–0.03)^a	0.42 (0.32–0.55)	0.61 (0.42–0.87)	0.96 (0.62–1.45)

b. Exclusion of children who already had allergy by the previous evaluation time
	CMA
	At 6 m (n = 59,560)	At 12 m (n = 59,422)	At 18 m (n = 58,855)	At 24 m (n = 58,326)	At 36 m (n = 58,195)
Formula consumption	aRR (95% CI)	aRR (95% CI)	aRR (95% CI)	aRR (95% CI)	aRR (95% CI)
Very early (0–3 months old)	1.00 (0.65–1.51)	1.15 (0.94–1.39)	0.82 (0.65–1.03)	1.01 (0.62–1.58)	0.59 (0.27–1.20)
Early (3–6 months old)	0.01 (0.00–0.05)^a	0.22 (0.11–0.38)	0.32 (0.21–0.47)	0.53 (0.25–1.10)	0.76 (0.29–1.98)
Late (6–12 months old)	–	0.01 (0.00–0.03)^a	0.61 (0.44–0.82)	0.78 (0.41–1.41)	1.36 (0.62–2.82)

The statuses of formula consumption (versus no consumption) and the following covariates were all included together in the model: sex, delivery mode, maternal allergic diseases, smoking and education, family income, early eczema, and older siblings as well as intake statuses of cow's milk protein before the evaluation time. Bold text represents statistical significance (p < 0.05)
aRR adjusted relative risk, CI confidence interval, CMA cow's milk allergy
^aThe result was very low as expected from the definition of CMA, which required no consumption of CM products including formula at the evaluation time

ISSN: 1710-1492