Table 1. Selected patients’ characteristics by high and low John Henryism.

	John Henryism
Characteristics	Low (Score ≤52), N=270	High (Score >52), N=255	P
Age yr, mean±SD	46.6±13.6	50.1±13.5	.003
% Age ≥ 60 yr	15.6	25.9	.003
% Male	61.1	61.6	.91
% Race			.08
White	14.5	8.3
Mixed	56.5	62.2
Black	29.0	29.5
% < High school	58.7	64.8	.15
% Poor/very poor	49.8	47.6	.63
% Married	45.7	39.0	.12
Months on dialysis, median [IQR]	44.6 [22.2, 88.0]	40.6 [16.0, 81.5]	.15
% Dialysis by catheter	11.9	11.1	.78
Kt/V, mean±SD	1.57±0.36	1.60±0.41	.32
Serum albumin in g/dL, mean±SD	3.73±0.39	3.76±0.38	.37
Serum creatinine in mg/dL, mean±SD	10.9±3.4	10.8±3.7	.67
Blood hemoglobin in mg/dL, mean±SD	10.4±1.8	10.7±1.8	.08
% Hypertension	91.1	92.5	.55
% Diabetic	18.5	20.4	.59
% Heart failure	10.4	9.9	.84
% Cerebrovascular disease	4.5	7.5	.14
% Other comorbidities	10.7	15.3	.12

The percentages of missing values were .6 for education, 9.3% for economic class, .4% for marital status, .4% for vascular access, 3.6% for Kt/V, 2.5% for albumin, .4% for creatinine, 2.5% for hemoglobin, .6% for heart failure.

Other comorbidities include asthma, chronic obstructive pulmonary disease, infections by virus B or virus C, cancer and peripheral vascular disease.

All categorical variables were consistent with the premises of the Pearson chi-squared test. Mann-Whitney test was used to test for differences in months on dialysis. For the other quantitative variable, independent sample t-test was used for comparing differences between the two John Henryism groups.