Indoor air pollution exposure from use of indoor stoves and fireplaces in association with breast cancer: a case-control study

Table 3 Association between duration (years) of indoor stove/fireplace use and breast cancer risk ^a

Exposure	Years of exposure	Controls	Cases	Age-adjusted OR	Multivariable-adjusted OR^b
Exposure	Years of exposure	(N)	(N)	(95% CI)	(95% CI)
Any indoor stove/fireplace use	No stove/fireplace use	781	757	1.00 (reference)	1.00 (reference)
	≤11.6 years	190	183	1.13 (0.89, 1.43)	1.15 (0.87, 1.51)
	11.7-21.6 years	190	172	1.02 (0.81, 1.30)	1.00 (0.76, 1.32)
	21.7-30.7 years	190	208	1.18 (0.94, 1.47)	1.13 (0.87, 1.46)
	>30.7 years	190	181	0.93 (0.74, 1.17)	0.95 (0.72, 1.25)
Wood burning ^c	No stove/fireplace use	781	757	1.00 (reference)	1.00 (reference)
	≤11.0 years	173	159	1.08 (0.84, 1.38)	1.07 (0.80, 1.42)
	11.1-21.4 years	173	156	1.03 (0.80, 1.31)	1.00 (0.75, 1.33)
	21.5-30.9 years	173	199	1.23 (0.97, 1.55)	1.20 (0.92, 1.55)
	>30.0 years	173	157	0.88 (0.69, 1.13)	0.88 (0.66, 1.17)
Synthetic log burning	No stove/fireplace use	781	757	1.00 (reference)	1.00 (reference)
	≤6.9 years	50	41	0.98 (0.63, 1.52)	1.12 (0.68, 1.82)
	7.0-16.7 years	50	69	1.69 (1.14, 2.50)	1.73 (1.11, 2.70)
	16.7-24.8 years	50	58	1.31 (0.88, 1.95)	1.29 (0.82, 2.03)
	>24.8 years	49	76	1.53 (1.05, 2.24)	1.50 (0.98, 2.31)

^aAmong Long Island, NY women, LIBCSP 1996-1997.
^bMultivariate OR adjusted for age, age at menarche, history of breastfeeding, hormone therapy use,
family history of breast cancer, parity, age at first birth, BMI at reference, education, smoking history,
alcohol intake, physical activity, race, religion, marital status.
^cWood burning excludes synthetic logs.

ISSN: 1476-069X