Table 3.

Cox regression analysis of the associations between the clinical variables in summer and mortality.

	HR	95% CI		p Value
		Lower	Upper
Step 1
Vitamin D quintile
5th quintile: >36.3 ng/mL	1.000
4th quintile: >30.3–≤36.3 ng/mL	2.378	0.829	6.821	0.107
3rd quintile: >23.6–≤30.3 ng/mL	1.755	0.540	5.704	0.350
2nd quintile: >18.0–≤23.6 ng/mL	4.136	1.391	12.292	0.011
1st quintile: ≤18.0 ng/mL	3.761	1.214	11.649	0.022
Age (years)	1.013	0,992	1.034	0.222
Gender	0.752	0.432	1.312	0.316
Ethnicity
White	1.000
Mixed race	1.332	0,672	2,642	0.411
Black	0,466	0,136	1,602	0.226
BMI (kg/m²)	0.947	0.899	0.998	0.042
Antiplatelet drugs use	0.792	0.440	1.425	0.437
Statin use	1.354	0.711	2.577	0.356
RAS inhibitors use	1.053	0.628	1.763	0.846
Calcitriol use in the first year of follow-up	0.928	0.542	1.588	0.784
Hemodialysis vintage (months)	1.002	0.996	1.008	0.533
Presence of hypertension	2.466	0.955	6.368	0.062
Presence of diabetes mellitus	1.566	0.874	2.807	0.132
Presence of atherosclerotic disease	1.423	0.834	2.429	0.195
CRP (mg/dL)	1.031	0.972	1.094	0.307
Step 6
5th quintile: >36.3 ng/mL	1.000
4th quintile: >30.3–≤36.3 ng/mL	2.474	0.885	6.917	0.084
3rd quintile: >23.6–≤30.3 ng/mL	1.677	0.544	5.167	0.368
2nd quintile: >18.0–≤23.6 ng/mL	4.302	1.603	11.541	0.004
1st quintile: ≤18.0 ng/mL	3.834	1.421	10.346	0.008
BMI (kg/m²)	0.952	0.909	0.997	0.035
Presence of hypertension	2.922	1.169	7.307	0.022
Presence of atherosclerotic disease	1.578	0.967	2.573	0.068

CRP: C-reactive protein; HR: hazard ratio; CI, confidence interval. BMI: body mass index; RAS: renin-angiotensin system.