Table 1. Risk factors of migraine: results from the multilevel model, adjusted for relative’s age at observation (Odds ratio, 95% CI).

Variables	Migraine Probands	MO Probands	MA Probands
Proband’s gender	0.79 (0.39–1.62)	0.61 (0.22–1.74)	1.16 (0.41–3.31)
Proband’s age at onset	0.75 (0.42–1.33)	0.50 (0.23–1.10)	1.21 (0.48–3.09)
Relative’s gender	2.86 (1.75–4.67)	4.15 (2.06–8.34)	1.86 (0.90–3.83)
Proband’s migraine subtype	0.78 (0.45–1.36)	–	–

Relative’s gender, proband’s gender and age-at-onset were included in the model as possible predictors of relatives’ affection status. Proband’s migraine subtype was also included as a predictor in an additional model.