Table 1. Demographic characteristics of elderly chronic kidney disease patients with or without vaccination.

	Unvaccinated (n = 2152)		Vaccinated (n = 2254)		p value
	Cases	%	Cases	%
Age (years)					< 0.001
55-64	975	45.31	497	22.05
65-74	651	30.25	1089	48.31
≥ 75	526	24.44	668	29.64
Gender					< 0.001
Female	951	44.19	884	39.22
Male	1201	55.81	1370	60.78
CCI					< 0.001
0	183	8.5	314	13.93
1	43	2	104	4.61
2	366	17.01	397	17.61
≥ 3	15600	72.49	1439	63.84
Hypertension					0.002
No	652	30.3	780	34.61
Yes	1500	69.7	1474	65.39
Diabetes					< 0.001
No	1197	55.62	1459	64.73
Yes	955	44.38	795	35.27
Dyslipidemia					< 0.001
No	1213	56.37	1429	63.4
Yes	939	43.63	825	36.6
Dialysis					< 0.001
No	1726	80.2	1893	83.98
Yes	426	19.8	361	16.02
Arrhythmia					0.605
No	1793	83.32	1891	83.9
Yes	359	16.68	363	16.1
Anemia					< 0.001
No	1761	81.83	1963	87.09
Yes	391	18.17	291	12.91
Pneumonia					0.044
No	1882	87.45	2015	89.4
Yes	270	12.55	239	10.6
Monthly income (NT$)					< 0.001
0	281	13.06	336	14.91
1-15840	346	16.08	502	22.27
15841-25000	979	45.49	1086	48.18
≥ 25001	546	25.37	330	14.64
Level of urbanization					< 0.001
Urban	1478	68.68	1422	63.09
Suburban	461	21.42	543	24.09
Rural	213	9.9	289	12.82
Geographic region					0.119
Northern	976	45.35	955	42.37
Central	587	27.28	684	30.35
Southern	542	25.19	565	25.07
Eastern	47	2.18	50	2.22

CCI, charlson comorbidity index; NT$, new taiwan dollars.