Table 2.

Relationship of QRS duration with incident atrial fibrillation

	Events/No. at risk	Person-years	Incidence rate Per 1000 person-years (95%CI)	Model 1* HR (95%CI)	P-value	Model 2† HR (95%CI)	P-value
QRS, <100 ms	1,457/11,898	224,657	6.5 (6.2, 6.8)	Ref	-	Ref	-
QRS, 100–119 ms	497/2,990	53,764	9.2 (8.5, 10.1)	1.26 (1.13, 1.40)	<0.001	1.13 (1.02, 1.26)	0.03
QRS, ≥120 ms	87/426	6,628	13.1 (10.6, 16.2)	1.60 (1.28, 1.99)	<0.001	1.35 (1.08, 1.68)	0.008
				P for trend <0.001		P for trend 0.002
QRS per 1-SD increase‡	2,041/15,314	285,050	7.2 (6.9, 7.5)	1.11 (1.07, 1.15)	<0.001	1.05 (1.01, 1.10)	0.01

^*Adjusted for age, sex, race, and study site.

^†Adjusted for Model 1 covariates plus body mass index, systolic blood pressure, smoking, diabetes, heart rate, coronary heart disease, and heart failure.

CI=confidence interval; HR=hazard ratio; Ref= Reference.

^‡1 standard deviation = 12ms.