Table 3. Subgroup Analyses by Age, Sex, Race, Exercise, Hypertension, and Coronary Heart Disease (N=24,730)^*.

	Model 1† HR (95%CI)	P-value	Model 2‡ HR (95%CI)	P-value	Interactionδ P-value
Age
<65 years	1.21 (1.07, 1.38)	0.0033	1.16 (1.02, 1.32)	0.029	0.12
≥65 years	1.05 (0.97, 1.14)	0.24	1.07 (0.98, 1.16)	0.13
Sex
Female	1.07 (0.97, 1.19)	0.16	1.07 (0.97, 1.19)	0.17	0.62
Male	1.13 (1.03, 1.24)	0.011	1.12 (1.02, 1.24)	0.019
Race
Black	1.15 (1.04, 1.27)	0.0049	1.16 (1.05, 1.28)	0.0046	0.12
White	1.06 (0.96, 1.17)	0.24	1.05 (0.95, 1.16)	0.34
Exercise
≥4 days/week	1.14 (1.01, 1.30)	0.042	1.14 (1.001, 1.30)	0.048	0.54
<4 days/week	1.08 (1.00, 1.18)	0.054	1.08 (0.99, 1.18)	0.072
Hypertension
No	1.10 (0.96, 1.27)	0.16	1.07 (0.93, 1.23)	0.34	0.51
Yes	1.10 (1.01, 1.19)	0.021	1.10 (1.02, 1.20)	0.018
Coronary heart disease
No	1.13 (1.04, 1.22)	0.0025	1.13 (1.04, 1.23)	0.0036	0.57
Yes	1.03 (0.90, 1.18)	0.63	1.02 (0.89, 1.17)	0.81

^*HRs presented for heart rate per 10 bpm increase.

^†Adjusted for age, sex, race, education, income, and region of residence.

^‡Adjusted for Model 1 covariates with the addition of systolic blood pressure, smoking, diabetes, left ventricular hypertrophy, antihypertensive medications, antiarrhythmic agents, statins, aspirin, warfarin, and coronary heart disease.

^δInteractions tested using Model 2.

CI=confidence interval; HR=hazard ratio.