Table 1. Comparison of Baseline Characteristics According to the Year of Dialysis Initiation.
| Characteristics | Total (n=32357) | 2005 (n=8066) | 2006 (n=7850) | 2007 (n=7876) | 2008 (n=8565) | p value* |
|---|---|---|---|---|---|---|
| Age (yrs) | 57.3±14.0 | 56.5±13.7 | 57.1±14.0 | 57.5±14.1 | 58.0±14.2 | <0.001 |
| Male (%) | 18994 (58.7) | 4688 (58.1) | 4560 (58.1) | 4675 (59.4) | 5071 (59.2) | 0.201 |
| Dialysis modality (ITT) | <0.001 | |||||
| PD | 7614 (23.5) | 2106 (26.1) | 1918 (24.4) | 1761 (22.4) | 1829 (21.4) | |
| HD | 24743 (76.5) | 5960 (73.9) | 5932 (75.6) | 6115 (77.6) | 6736 (78.6) | |
| Healthcare Security System | <0.001 | |||||
| National Health Insurance | 27919 (86.3) | 6802 (84.3) | 6725 (85.7) | 6814 (86.5) | 7578 (88.5) | |
| Medical Aid | 4438 (13.7) | 1264 (15.7) | 1125 (14.3) | 1062 (13.5) | 987 (11.5) | |
| Comorbidities | ||||||
| Diabetes mellitus | 16211 (50.1) | 3835 (47.5) | 3862 (49.2) | 3999 (50.8) | 4515 (52.7) | <0.001 |
| Myocardial infarction | 1166 (3.6) | 291 (3.6) | 308 (3.9) | 279 (3.5) | 288 (3.4) | 0.280 |
| Congestive heart failure | 4772 (14.7) | 1280 (15.9) | 1190 (15.2) | 1145 (14.5) | 1157 (13.5) | <0.001 |
| Peripheral vascular disease | 1911 (5.9) | 392 (4.9) | 401 (5.1) | 473 (6.0) | 645 (7.5) | <0.001 |
| Cerebrovascular disease | 4041 (12.5) | 938 (11.6) | 972 (12.4) | 1031 (13.1) | 1100 (12.8) | 0.028 |
| Dementia | 448 (1.4) | 88 (1.1) | 91 (1.2) | 115 (1.5) | 154 (1.8) | <0.001 |
| Chronic pulmonary disease | 5238 (16.2) | 1248 (15.5) | 1248 (15.9) | 1261 (16.0) | 1481 (17.3) | 0.010 |
| Connective tissue disease | 894 (2.8) | 276 (3.4) | 190 (2.4) | 218 (2.8) | 210 (2.5) | <0.001 |
| Peptic ulcer disease | 4720 (14.6) | 1167 (14.5) | 1151 (14.7) | 1210 (15.4) | 1192 (13.9) | 0.071 |
| Hemiparesis | 494 (1.5) | 108 (1.3) | 115 (1.5) | 139 (1.8) | 132 (1.5) | 0.167 |
| Liver disease | 3474 (10.7) | 823 (10.2) | 840 (10.7) | 827 (10.5) | 984 (11.5) | 0.048 |
| Any malignancy | 1983 (6.1) | 441 (5.5) | 459 (5.8) | 498 (6.3) | 585 (6.8) | 0.002 |
| Modified CCI | <0.001 | |||||
| 0 | 8468 (26.2) | 2193 (27.2) | 2172 (27.7) | 1993 (25.3) | 2110 (24.6) | |
| 1-2 | 10489 (32.4) | 2777 (34.4) | 2569 (32.7) | 2512 (31.9) | 2631 (30.7) | |
| 3-4 | 8418 (26.0) | 1959 (24.3) | 1976 (25.2) | 2099 (26.7) | 2384 (27.8) | |
| ≥5 | 4982 (15.4) | 1137 (14.1) | 1133 (14.4) | 1272 (16.2) | 1440 (16.8) |
ITT, intention-to-treat; PD, peritoneal dialysis; HD, hemodialysis; CCI, Charlson Comorbidity Index.
Age is expressed as the mean±SD, and all other data are expressed as the number (%).
*p-values are calculated by the comparison according to the year of dialysis initiation.