Table 2.

Univariable Conditional Logistic Regression Analysis of Characteristics associated with BC among TPW

Characteristics	Cases		Controls		ORc	95%CI	p-valuea
	No.	%	No.	%
Family history of BC
No	211	82.1	249	96.9	1
Yes	46	17.9	8	3.1	6.43	2.89-14.25	<0.001*
History of benign breast tumor
No	209	81.3	235	91.3	1
Yes	48	18.7	22	8.6	2.37	1.39-4.05	0.001*
Age at menarche (yrs)
≥14	83	32.3	140	54.5	1
<14	174	67.7	117	45.5	2.54	1.74-3.72	<0.001*
Parity
No	193	75.1	172	66.9	1
Yes	64	24.9	85	33.1	0.68	0.46-1.00	0.051
Miscarriage
No	186	72.4	214	83.3	1
Yes	71	27.6	43	16.7	1.93	1.24-3.00	0.003*
Contraceptive use
No	90	35	162	63	1
Yes	167	65	95	37	3.32	2.22-4.96	<0.001*
Active smoking
No	248	96.5	251	97.7	1
Yes	9	3.5	6	2.3	1.5	0.53-4.21	0.437
Passive smoking
No	153	59.5	198	77.1	1
Yes	104	40.5	59	22.9	2.22	1.46-3.37	<0.001*
Alcohol consumption
No	251	97.7	252	98.1	1
Yes	6	2.3	5	1.9	1.2	0.32-4.61	0.761
Multivitamin use
No	227	88.3	168	65.4	1
Yes	30	11.7	89	34.6	0.26	0.16-0.42	<0.001*
BMI (kg/m2)
18.5-22.9	89	34.7	122	47.4	1
23.0-24.9	44	17.1	54	21	1.18	0.71-1.97	0.531
25.0-29.9	88	34.2	41	16	3.07	1.87-5.05	<0.001*
≥30.0	26	10.1	10	3.9	3.68	1.64-8.25	<0.001*
<18.5	10	3.9	30	11.7	0.44	0.22-0.95	0.036*

^a, Univariable analysis performed on 257 matched pairs;BC, Breast Cancer;OR_c, crude odds ratio;CI, confidence interval;

^*, Significant at p-value <0.05.