TABLE 2.

Separate and joint associations of socioeconomic status and cardiorespiratory fitness with risk of heart failure

Exposure categories	Events/Total	Model 1		Model 2		Model 3
		HR (95% CI)	p‐value	HR (95% CI)	p‐value	HR (95% CI)	p‐value
Socioeconomic status
Per SD increase in SES	364/1831	1.41 (1.27–1.58)	<.001	1.27 (1.14–1.42)	<.001	1.27 (1.14–1.43)	<.001
High SES	146/922	ref		ref		ref
Low SES	218/909	1.67 (1.35–2.07)	<.001	1.43 (1.15–1.79)	.001	1.41 (1.13–1.76)	.002
CRF (ml/kg/min)
Per SD increase in CRF	364/1831	0.62 (0.55–0.70)	<.001	0.78 (0.68–0.90)	<.001	0.78 (0.68–0.89)	<.001
Low CRF	226/916	ref		ref		ref
High CRF	138/915	0.49 (0.40–0.61)	<.001	0.70 (0.55–0.89)	.003	0.69 (0.55–0.88)	.002
Socioeconomic status and CRF (ml/kg/min) combination
High SES‐Low CRF	88/390	ref		ref		NA
Low SES‐ Low CRF	138/526	1.45 (1.11–1.89)	.007	1.32 (1.01–1.74)	.045	NA
High SES‐High CRF	58/532	0.43 (0.31–0.60)	<.001	0.62 (0.43–0.89)	.009	NA
Low SES‐High CRF	80/383	0.82 (0.61–1.11)	.21	1.01 (0.73–1.39)	.96	NA

Cut‐offs for SES and CRF were based on the median values.

Model 1: Adjusted for age.

Model 2: Model 1 plus systolic blood pressure, body mass index, heart rate, smoking status, history of type 2 diabetes, history of CHD, total cholesterol, high‐density lipoprotein cholesterol, and physical activity.

Model 3: Model 2 plus CRF for SES and SES for CRF.

Abbreviations: CHD, coronary heart disease; CI, confidence interval; CRF, cardiorespiratory fitness; HR, hazard ratio; NA, not applicable; ref, reference; SD, standard deviation; SES, socioeconomic status.