Table 3.

Predictors of breast-milk iodine concentration* of South Australian women

	Adjusted estimated ratio†	95 % CI	Adjusted P value
Smoking	0·5	0·4, 0·6	<0·01
5-unit increase in BMI	1·0	1·0, 1·1	0·50
Alcohol consumption	1·2	1·0, 1·4	0·03
Non-Caucasian ethnicity	1·4	1·3, 1·6	<0·01
Parity ≥1	1·1	1·0, 1·2	0·05
Completed secondary education	1·1	1·0, 1·2	0·12

^*Breast-milk iodine concentration as a continuous variable.

^†Adjusted for cohort (the effects of pre and post fortification), iodine supplement use, maternal BMI, smoking, alcohol consumption, parity, ethnicity and secondary education.