Family history as a risk factor for recurrent hospitalization for lone atrial fibrillation: a nationwide family study in Sweden

Table 3 Results from Cox proportional hazard models for individuals with LAF in the Swedish population (1987–2009): sibling analysis (n=20,373) and parent-sibling analysis (n=13,525)

	Model 2.A	Model 2.B	Model 3.A	Model 3.B
	HR (95% CI)	HR (95% CI)	HR (95% CI)	HR (95% CI)
AF in sibling(s) (yes/no)	1.30 (1.22-1.38)	1.46 (1.30-1.65)	1.28 (1.18-1.39)	1.48 (1.24-1.75)
AF in parent(s)			1.21 (1.14-1.28)	1.16 (1.10-1.23)
Sex (Reference: females)		1.21 (1.15-1.27)		1.26 (1.18-1.34)
Age at diagnosis of AF (yearly increase)		1.02 (1.02-1.02)		1.02 (1.02-1.02)
AF in Sibling (age at diagnosis of AF)		0.99 (0.98-0.99)
AF in sibling (sex)		0.83 (0.72-0.95)		0.76 (0.63-0.93)
AF in parent(s) (age at diagnosis of AF)				0.99 (0.98-0.997)

Model 2.A: sibling history of AF was included as a covariate (yes/no). Model 2.B: we also included sex, age at diagnosis of LAF (centered at the mean value), and terms for the interactions between sibling history of AF and age/sex. The interaction terms were only included in the model if the p-values were <0.05. Both model 2A and 2B were adjusted for the number of siblings to the proband case. Model 3.A, sibling history of AF and parental history of AF were included as covariates (yes/no). Model 3.B: included sex, age at diagnosis of LAF (age at LAF), terms for the interactions between sibling history of AF and parental history of AF and terms for the interactions between sibling history of AF/parental history of AF and age/sex. The interaction terms were only included in the model if the p-values were <0.05.

ISSN: 1471-2261