Table 2.

Incidence rates and hazard ratios of atrial fibrillation by quartile of serum uric acid

Quartile of SUA	Number at risk	Number developing AF	Incidence rate of AF per 1000 person-years	Age, gender and race-adjusted HR (95% C.I)
Baseline quartiles
Quartile 1 (<5.0 mg/dl)	3880	186	3	1 (Reference)
Quartile 2 (5.0-5.9 mg/dl)	3919	243	4	1.04(0.83-1.30)
Quartile 3 (6.0-7.0 mg/dl)	3927	297	5	1.30(1.04-1.62)
Quartile 4 (>7.0 mg/dl)	3656	359	8	1.74(1.39-2.17)
p for trend			<0.01	<0.01
Mean quartiles *
Quartile 1 (<5.0 mg/dl)	3584	158	3	1 (Reference)
Quartile 2 (5.0-5.9 mg/dl)	3461	213	4	1.29(1.02-1.63)
Quartile 3 (6.0-7.0 mg/dl)	3390	250	5	1.40(1.11-1.78)
Quartile 4 (>7.0 mg/dl)	3448	319	7	2.00(1.58-2.52)
p for trend			<0.01	<0.01

^*Excludes cases of AF between visits 1 and 2 and those who did not attend visit 2.

HR: Hazard ratio, CI: confidence interval