Table 3.

Risk of Breast Cancer Associated With Migraine History Stratified by NSAID Use

NSAID Use Category	No. of Incident Cases Without a Migraine History	No. of Incident Cases With a Migraine History	Adjusted for Age and Race/Ethnicity		Multivariate Adjusted Analysis*
			HR	95% CI	HR	95% CI
Not currently using NSAIDs
Any breast cancer	2,355	247	0.90	0.79 to 1.03	0.89	0.78 to 1.02
Invasive breast cancer	1,930	211	0.94	0.82 to 1.09	0.93	0.80 to 1.07
ER- and PR-positive invasive breast cancer	1,080	105	0.83	0.68 to 1.02	0.79	0.64 to 0.98†
Current NSAID users
Any breast cancer	1,241	164	0.86	0.73 to 1.02	0.88	0.74 to 1.04
Invasive breast cancer	1,042	135	0.85	0.71 to 1.02	0.87	0.72 to 1.04
ER- and PR-positive invasive breast cancer	613	80	0.87	0.69 to 1.10	0.88	0.69 to 1.12
Current NSAID users for < 3 years
Any breast cancer	586	57	0.74	0.56 to 0.97†	0.74	0.56 to 0.97†
Invasive breast cancer	488	52	0.81	0.60 to 1.07	0.81	0.60 to 1.08
ER- and PR-positive invasive breast cancer	276	34	0.95	0.66 to 1.35	0.96	0.66 to 1.39
Current NSAID users for ≥ 3 years
Any breast cancer	655	107	0.96	0.78 to 1.18	0.98	0.79 to 1.21
Invasive breast cancer	554	83	0.89	0.70 to 1.12	0.91	0.72 to 1.15
ER- and PR-positive invasive breast cancer	337	46	0.81	0.60 to 1.11	0.83	0.61 to 1.14

Abbreviations: NSAID, nonsteroidal anti-inflammatory drug; HR, hazard ratio; ER, estrogen receptor; PR, progesterone receptor.

^*Multivariate adjusted HRs are adjusted for age, race/ethnicity, and the following baseline characteristics: hysterectomy, use of menopausal hormones, alcohol consumption, smoking status, and regular coffee consumption. The 3,332 women with a known NSAID use history but with missing data for one or more of the covariates adjusted for in the multivariate models were excluded from these analyses.

^†P < .05.