Table 1

General characteristics of the study population and haemodialysis units by hospitalisation after haemodialysis

	Hospitalisation after haemodialysis (N=4 751 047)
	Yes		No
Variables	N/mean	Per cent/SD	N/mean	Per cent/SD	p Value
Patient characteristics
Age (years)
≤49	4124	0.41	1 011 407	99.59	<0.0001
50–59	6743	0.52	1 278 756	99.48
60–69	7889	0.63	1 241 225	99.37
≥70	9241	0.77	1 191 662	99.23
Sex
Male	15 815	0.58	2 719 129	99.42	0.0003
Female	12 182	0.60	2 003 921	99.40
Type of insurance coverage
NHI	20 734	0.57	3 621 256	99.43	<0.0001
Medical aid	7263	0.65	1 101 794	99.35
Experience of prehospitalisation during 1 year
Yes	15 647	0.89	1 743 611	99.11	<0.0001
No	12 350	0.41	2 979 439	99.59
Duration of illness (years)
2–3	2816	0.73	381 554	99.27	<0.0001
3–4	3624	0.68	529 343	99.32
4–5	3154	0.65	483 078	99.35
5–6	3806	0.65	581 142	99.35
>6	14 597	0.53	2 747 933	99.47
CCI
0	3351	0.42	797 328	99.58	<0.0001
1, 2	12 579	0.58	2 173 291	99.42
3, 4	9824	0.70	1 385 868	99.30
5+	2243	0.61	366 563	99.39
Haemodialysis unit characteristics
Type of medical institution
General hospital (N=234)	15 137	0.82	1 825 112	99.18	<0.0001
Clinic or hospital (N=395)	12 860	0.44	2 897 938	99.56
Presence of nephrologist
Yes (N=114)	8815	0.79	1 102 400	99.21	<0.0001
No (N=515)	19 182	0.53	3 620 650	99.47
Total number of doctors who provided haemodialysis	1.99	±1.57	1.83	±1.40	<0.0001
Proportion of haemodialysis patient care specialists	83.59	±33.80	84.10	±33.09	0.0107
Total number of nurses who provided haemodialysis	10.84	±6.85	11.10	±7.04	<0.0001
Proportion of nurses experienced in haemodialysis	74.53	±17.09	75.22	±16.65	<0.0001
Volume of haemodialysis per doctor	1.77	±0.97	1.97	±1.06	<0.0001
Number of beds	330.98	±382.58	246.18	±375.48	<0.0001
Emergency equipment in haemodialysis unit
Yes (N=573)	26 483	0.59	4 469 487	99.41	0.1794
No (N=56)	1514	0.59	253 563	99.41
Fulfilment rate of criteria for duration of water analysis	90.74	±19.81	90.31	±19.93	0.0004
Number of haemodialysis machines	34.40	±18.18	34.36	±18.70	0.6967
Proportion of medical cost due to CKD	37.85	±38.61	53.05	±40.71	<0.0001
Total	27 997	0.59	4 723 050	99.41

CCI, Charlson Comorbidity Index; CKD, chronic kidney disease; NHI, National Health Insurance.