Table 1.

Baseline characteristics stratified by the occurrence of incident atrial fibrillation

Characteristic (N=34691)	No incident AF (n=33224)	Incident AF (n=1467)	P value*
Age, years	53 (49–58)	58 (52–64)	<0.001
Race/ethnicity, %			<0.001
White	31290 (95.0)	1427 (98.1)
Other	1647 (5.0)	28 (1.9)
Body mass index, kg/m2	24.9 (22.5–28.3)	26.1 (23.2–30.3)	<0.001
Height, meters	1.65 (1.60–1.68)	1.65 (1.63–1.70)	<0.001
Hypertension, %			<0.001
Yes	8550 (25.7)	610 (41.6)
No	24674 (74.3)	857 (58.4)
Diabetes, %			<0.001
Yes	870 (2.6)	64 (4.4)
No	32354 (97.4)	1403 (95.6)
Hypercholesterolemia, %			<0.001
Yes	9988 (30.1)	501 (34.2)
No	23236 (69.9)	966 (65.9)
Smoking, %			0.06
Current/past	16020 (48.3)	744 (50.8)
Never	17180 (51.8)	721 (49.2)
Alcohol consumption, %			0.05
Rarely/never	14682 (44.2)	667 (45.5)
1–3 drinks per month	4404 (13.3)	179 (12.2)
1–6 drinks per week	10723 (32.3)	444 (30.3)
≥1 drink per day	3406 (10.3)	176 (12.0)
Highest education level, %			0.003
< bachelor’s degree	18153 (55.6)	870 (60.1)
Bachelor’s degree	7779 (23.8)	305 (21.1)
Master’s degree or doctorate	6722 (20.6)	272 (18.8)
Physical activity, kcal/week	586 (196–1340)	549 (175–1303)	0.05
Hormone replacement therapy, %			<0.001
Current	13641 (41.1)	676 (46.2)
Past	2845 (8.6)	156 (10.7)
Never	16675 (50.3)	632 (43.2)
Number of screening tests for colon cancer	2 (0–3)	2 (1–3)	0.19
Number of screening tests for breast cancer	7 (4–8)	7 (4–8)	0.85

AF=Atrial fibrillation. Data are medians (interquartile range) or counts (percentages). Number of observations across categories may not sum to the given numbers because of missing data.

^*Continuous and categorical variables were compared using Kruskal-Wallis tests and chi-square tests, respectively.