Table 3.

Associations between different estrogen-related variables and the risk of bladder cancer among Egyptian women

Estrogen-related main predictor variablea	Controls	All Cases		Only SCCb		Only UCc
		N	AORd (95% CIe)f	N	AOR (95% CI)f	N	AOR (95% CI)f
Age at first pregnancy (y)
≤18	282	87	ref	45	ref	42	ref
>18	198	121	1.98 (1.41, 2.77)	62	1.98 (1.27, 3.09)	59	1.99 (1.25, 3.18)
Number of pregnancies
≤7	257	126	ref	67	ref	59	ref
>7	236	87	0.66 (0.47, 0.94)	44	0.76 (0.48, 1.20)	43	0.62 (0.39, 0.99)
Menopause
No	152	21	ref	17	ref	4	ref
Yes
At age (y)
≥50	160	60	2.71 (1.39, 5.29)	22	2.22 (0.91, 5.44)	38	6.13 (1.86, 20.16)
45 to 49	109	64	4.06 (2.20, 7.49)	35	4.28 (1.98, 9.24)	29	7.46 (2.35, 23.67)
<45	72	68	6.26 (3.46, 11.34)	37	5.63 (2.74, 11.57)	31	12.78 (4.05, 40.29)
Oral contraceptive
No	316	171	ref	89	ref	82	ref
Yes	168	36	0.44 (0.29, 0.65)	19	0.36 (0.21, 0.63)	19	0.58 (0.33, 1.03)

^aFor each main predictor variable, we performed a logistic regression model;

^bsquamous cell carcinoma;

^curothelial [cell] carcinoma;

^dadjusted odds ratio;

^econfidence interval;

^fadjusted for age, residence, history of schistosomiasis, and history of urinary tract infection.