Table 1. Breast cancer risk in South Asian first-generation migrants in England by sociodeomographic, reproductive and other variables: univariable analysis.

	Category per unit increase	ORa	95% CIb	P-value
Socio-demographic characteristics
Age on arrival in UK	Per 5 years	1.00	0.98, 1.02	0.77
Migrated via East Africa	Yes vs no	1.07	0.76, 1.51	0.70
Years of education	0	1	—	—
	1–7	1.44	0.80, 2.59	0.23
	8–13	2.18	1.24, 3.83	0.01
	⩾14	2.10	1.14, 3.87	0.02
Social class	Nonmanual vs manual	1.64	1.16, 2.33	0.01
Reproductive factors
Age at menarche (years)	Per year	0.92	0.83, 1.02	0.10
Age at first birth (years)	<20	1	—	—
	20–24	0.97	0.61, 1.55	0.91
	25–29	1.68	1.02, 2.77	0.04
	30+	1.49	0.77, 2.90	0.24
	Nulliparous	1.38	0.64, 2.96	0.42
Parity	1–2	1	—	—
	3–4	1.09	0.75, 1.59	0.64
	5–7	0.72	0.43, 1.22	0.22
	⩾8	0.44	0.12, 1.62	0.22
	Nulliparous	1.11	0.55, 2.24	0.77
Breast feedingc	Ever vs never	0.70	0.47, 1.06	0.09
Duration of breast feeding	<6 months	1	—	—
	6–11 months	1.27	0.69, 2.34	0.45
	12–23 months	0.90	0.50, 1.62	0.74
	24–47 months	1.14	0.63, 2.07	0.66
	⩾48 months	0.91	0.48, 1.74	0.77
	Never	1.50	0.92, 2.46	0.11
Menopausal status	Post vs pre	1.45	0.92, 2.30	0.11
Median age at menopaused	Per year	1.03	0.99, 1.08	0.14
Familial factors
Family history of breast cancer	Yes vs no	1.92	0.94, 3.91	0.07
Parental consanguinity	Yes vs no	1.31	0.73, 2.35	0.37
Environmental factors
Adult height	Per 5 cm	1.05	0.91, 1.22	0.49
Leg length	Per 5 cm	0.94	0.80, 1.10	0.43
Waist : hip ratio	Per 10%	1.05	0.88, 1.26	0.57
Waist circumference	Per 10 cm	1.19	1.03, 1.39	0.02
BMIe at interview	Per 3 kg m−2	1.08	0.97, 1.19	0.15
METf score at age 12 years	Per 20%	0.99	0.95, 1.04	0.78
METf score at age 30 years	Per 20%	0.97	0.94, 1.01	0.20
Total energy	Per 500 kcal	1.04	0.89, 1.23	0.61
NSPg per 1000 kcal	Per 2 g/1000 kcal	0.84	0.73, 0.97	0.02
% energy from fat	Per 5%	0.92	0.80, 1.05	0.22

^aOR=odds ratio (estimated from a conditional logistic regression model hence controlled for age and GP).

^bCI=confidence interval.

^cAmong parous women.

^dAmong postmenopausal women.

^eBMI=body mass index.

^fMET=metabolic equivalent score per week.

^gNSP=nonstarch polysaccharides.