Table 2. Showing binary analysis results comparing cases and controls for risk factors for breast cancer development among African women in Tanzania.

RISK FACTOR	CASE	CONTROL	OR	P-value	95% CI
Family history of breast cancer	16 (15.2%)	10 (5.3%)	3.2	0.006	1.40–7.40
Adolescent obesity	46 (43.8%)	53 (27.9%)	2.0	0.0007	1.20–3.32
Cigarette Smoking	12 (11.4%)	5 (2.6%)	4.7	0.004	1.63–13.96
Alcohol intake	43 (41.0%)	62 (32.6%)	1.43	0.15	0.87–2.35
First delivery below 35 yrs.	96 (91.4%)	182 (95.8%)	0.79	0.79	0.12–4.78
Null parity	8 (7.6%)	6 (3.2%)	2.5	0.94	0.85–7.5
Contraceptive use a	56 (53.3%)	99 (52.1%)	1.05	0.84	0.65–1.69
Breast feeding	96 (98%)	184 (99.5%)	0.26	0.28	0.02–2.90
Infertility drug use b	14 (13.3%)	26 (13.9%)	0.97	0.93	0.48–1.95
Age at menarche (years)			1.13	0.83	0.36–3.58
< 12	5 (4.7%)	8 (4.2%)
≥ 12	100 (95.2%)	182 (95.8%)
Age at menopause c (years)
< 45	16 (28.1%)	10 (14.7%)	2.26	0.07	0.93–5.49
≥ 45	41 (71.9%)	58 (85.3%)
Mean age in years (range)	49.55±13.8 (25–85)	44.95±13.5 (21–84)	0.97	0.006	0.96–0.99
Residence
Urban	55 (52.4%)	126 (66.3%)	0.56	0.019	0.343–0.91
Rural	50 (47.6%)	64 (33.7%)

^a Any reported use of a modern contraceptive method.

^b Any reported modern medicine taken to boost ovulation or sustain a pregnancy.

^c Only 57 cases and 68 controls had attained menopause at the time of the study.