Table 2.

Prevalence of headache and migraine by age, gender, race and income

	No headache			Migraine with and without aura
	n	%	Relative risk (95 % confidence interval)	n	%	Relative risk (95 % confidence interval)
Age
5, 6	109	24.8	Reference	14	3.2	Reference
7, 8	127	18.7	0.7 (0.6–0.9)	42	6.2	1.9 (1.1–3.5)
9, 10+	109	14.8	0.6 (0.5–0.8)	62	8.4	2.6 (1.5–4.7)
Gender
Female	159	17.7	Reference	55	6.1	Reference
Male	186	19.4	1.1 (0.9–1.3)	63	6.6	1.1 (0.7–1.5)
Race
White	201	18.6	Reference	65	6.0	Reference
Non-white	126	18.0	1.0 (0.8–1.2)	51	7.3	1.2 (0.8–1.7)
Not stated	18	24.0	1.3 (0.8–2.0)	2	2.7	0.4 (0.1–1.8)
Income class
A, B	49	14.9	Reference	13	3.9	Reference
C	178	18.2	1.2 (0.9–1.6)	66	6.8	1.7 (1.0–3.1)
D, E	118	21.4	1.4 (1.1–1.9)	39	7.1	1.8 (1.0–3.3)
Total	345	18.6		118	6.4