Table 3.

Associations between five-year job tenure prior to age 45, parity and prevalence of breast cancer among female flight attendants^a

	N Cases	N Non-Cases	Odds Ratio (95% CI)
Lifetime job tenure	108	2620	0.99 (0.91, 1.10)
Job tenure prior to age 45)b	90	1151	1.09 (0.91, 1.29)
Parity (lifetime job tenure)
Nulliparous	26	1020	1.27 (0.94, 1.71)
1 to 2	68	1376	0.95 (0.84, 1.06)
3+	68	1161	1.22 (1.05, 1.42)
Parity (tenure prior to age 45)b
Nulliparous	19	484	1.44 (0.83, 2.49)
1 to 2	50	896	0.95 (0.78, 1.17)
3+	58	848	1.39 (1.06, 1.81)

^aAll models are adjusted for age, overweight, education, parity and smoking history

^bModels for tenure prior to age 45 are restricted to participants age 45 or over