Mid- to late-life migraine diagnoses and risk of dementia: a national register-based follow-up study

Table 4 Hazard rate ratios of dementia associated with migraine diagnoses grouped by sex or educational level (N = 62,578)

Characteristics	No. of individuals	Dementia cases/person-years	HR (95% CI)	P value for interaction
Sex				0.6^a
Men
Without migraine	13,617	186/102,687	1.00
With migraine	2882	57/21,913	1.39 (1.03–1.88)
Women
Without migraine	38,104	454/299,319	1.00
With migraine	7975	150/62,013	1.54 (1.28–1.86)
Educational level				0.8^b
Low
Without migraine	17,757	292/147,296	1.00
With migraine	3799	92/31,028	1.47 (1.16–1.87)
Medium
Without migraine	20,366	229/159,620	1.00
With migraine	4173	72/32,484	1.45 (1.11–1.89)
High
Without migraine	13,598	119/95,090	1.00
With migraine	2885	43/20,414	1.64 (1.16–2.33)

In all models, any migraine diagnosis was investigated as exposure. All models were adjusted for sex, all other migraine diagnoses, country of origin, marital status, educational level, other headache diagnoses, psychiatric morbidities and Charlson Comorbidity Index
HR Hazard rate ratios, 95% CI 95% confidence intervals
^a Interaction tested between migraine and sex
^b Interaction tested between migraine and educational levels

ISSN: 1129-2377