TABLE 2.

Association between brachial and central SBP with the composite cardiovascular outcome, stratified by whether aged 65 years and older

	bSBPb		cSBPb		ebSBPb		ecSBPb
Modela	HR (95% CI)e	P value	HR (95% CI)e	P value	HR (95% CI)	P value	HR (95% CI)	P value	AIC	P valuec	c-statistic	P valued
Middle-aged group, age <65 years (N = 243/17 383)
Model 1	1.12 (1.04, 1.21)	0.002	–	–	–	–	–	–	4429.50	–	0.704	–
Model 2	1.13 (1.05, 1.21)	0.002	–	–	–	–	1.05 (1.00, 1.09)	0.03	4426.61	0.03	0.707	0.32
Model 3	–	–	1.14 (1.06, 1.23)	<0.001	–	–	–	–	4427.23	–	0.705	–
Model 4	–	–	1.14 (1.06, 1.23)	<0.001	0.97 (0.93, 1.01)	0.11	–	–	4426.61	0.11	0.707	0.39
Older adult group, age> = 65 (N = 566/16906)
Model 1	1.11 (1.06, 1.17)	<0.001	–	–	–	–	–	–	10246.66	–	0.675	–
Model 2	1.11 (1.06, 1.17)	<0.001	–	–	–	–	1.00 (0.97, 1.03)	0.95	10248.65	0.94	0.675	0.57
Model 3	–	–	1.11 (1.06, 1.17)	<0.001	–	–	–	–	10247.08	–	0.675	–
Model 4	–	–	1.11 (1.06, 1.17)	<0.001	1.01 (0.98, 1.04)	0.51	–	–	10248.65	0.51	0.675	0.89

^aAll models were adjusted for age, sex, current smoker, diabetes, use of antihypertensive drug, BMI, high cholesterol level, heart rate and chronic kidney disease.

^bbSBP indicates brachial systolic blood pressure; cSBP indicates central systolic blood pressure; ebSBP represented the residual generated from bSBP∼cSBP (without the adjustment of other risk factors); and ecSBP represented the residual generated from cSBP∼bSBP (without the adjustment of other risk factors).

^cThe P value was obtained from log-likelihood ratio test. Model 2 was compared with model 1 whereas model 4 was compared with model 3.

^dThe P value was for the comparison of c-statistics. Model 2 was compared with model 1 whereas model 4 was compared with model 3.

^eHazard ratio for blood pressure was expressed per increment of 10 mmHg.