Table 1. Demographics of study subjects in 2 different cohorts with and without schizophrenia.
CCI: Charlson Comorbidity Index, DM: diabetes mellitus, EPO: erythropoietin, NHI: National Health Insurance.
| Schizophrenia Cohort | Dialysis Cohort | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Control subgroup (n = 54361) | ESRD-free schizophrenia subgroup (n = 54361) | P value | Comparison subgroup (n = 933) | Dialysis-schizophrenia subgroup (n = 311) | P value | |||||
| Age, years a (%) | 1.0000 | 1.0000 | ||||||||
| Mean (SD) | 41.1 (12.6) | 41.1 (12.5) | 55.0 (12.8) | 54.9 (12.7) | ||||||
| 20–39 | 28423 | (52.3) | 28423 | (52.3) | 114 | (12.2) | 38 | (12.2) | ||
| 40–49 | 14747 | (27.1) | 14747 | (27.1) | 240 | (25.7) | 80 | (25.7) | ||
| 50–59 | 6344 | (11.7) | 6344 | (11.7) | 249 | (26.7) | 83 | (26.7) | ||
| 60–69 | 3158 | (5.8) | 3158 | (5.8) | 207 | (22.2) | 69 | (22.2) | ||
| >70 | 1689 | (3.1) | 1689 | (3.1) | 123 | (13.2) | 41 | (13.2) | ||
| Gender (%) | 1.0000 | 1.0000 | ||||||||
| Male | 29804 | (54.8) | 29804 | (54.8) | 393 | (42.1) | 131 | (42.1) | ||
| Female | 24557 | (45.2) | 24557 | (45.2) | 540 | (57.9) | 180 | (57.9) | ||
| NHI registration location (%) | <0.0001 | 0.2675 | ||||||||
| City | 16747 | (30.8) | 14039 | (25.8) | 235 | (25.2) | 76 | (24.4) | ||
| Township | 15943 | (29.3) | 15509 | (28.5) | 318 | (34.1) | 93 | (29.9) | ||
| Rural area | 21671 | (39.9) | 24813 | (45.7) | 380 | (40.7) | 142 | (45.7) | ||
| Income | <0.0001 | <0.0001 | ||||||||
| Poor | 185 | (0.3) | 5519 | (10.1) | 13 | (1.4) | 44 | (14.1) | ||
| Low income | 7582 | (14.0) | 23787 | (43.8) | 195 | (20.9) | 116 | (37.3) | ||
| Middle income | 43635 | (80.3) | 24348 | (44.8) | 676 | (72.4) | 138 | (44.4) | ||
| High income | 2959 | (5.4) | 707 | (1.3) | 49 | (5.3) | 13 | (4.2) | ||
| CCI score | <0.0001 | 0.0382 | ||||||||
| 0 | 47046 | (86.5) | 45841 | (84.3) | 110 | (11.8) | 54 | (17.4) | ||
| 1–2 | 5841 | (10.8) | 7007 | (12.9) | 259 | (27.8) | 77 | (24.8) | ||
| >2 | 1474 | (2.7) | 1513 | (2.8) | 564 | (60.5) | 180 | (57.9) | ||
| Comorbidity | ||||||||||
| DM | 1567 | (2.9) | 2328 | (4.3) | <0.0001 | 453 | (48.6) | 139 | (44.7) | 0.2380 |
| Hypertension | 2430 | (4.5) | 2630 | (4.8) | 0.0040 | 517 | (55.4) | 166 | (53.4) | 0.5319 |
| Renal care b | ||||||||||
| Nephrologist visit | 724 | (77.6) | 205 | (65.9) | <0.0001 | |||||
| EPO treatment | 430 | (46.1) | 113 | (36.3) | 0.0027 | |||||
| Dialysis modality c | 0.0004 | |||||||||
| Peritoneal dialysis | 76 | (9.3) | 7 | (2.7) | ||||||
| Hemodialysis | 739 | (90.7) | 255 | (97.3) | ||||||
| Permanent vascular access created in advance c , d | 188 | (25.4) | 53 | (20.8) | 0.1347 | |||||
| First time dialysis setting | 0.3333 | |||||||||
| Emergency | 47 | (5.8) | 18 | (6.9) | ||||||
| Out-patient clinic | 142 | (17.4) | 36 | (13.7) | ||||||
| Hospitalization | 626 | (76.8) | 208 | (79.4) | ||||||
a Age to be initially followed for schizophrenia cohort and age of initiating regular dialysis cohort
b Conditions investigated six months prior to initiating regular dialysis
c for patients continuously receiving dialysis for three months immediately after the index date
d for patients on hemodialysis, and created vascular access at least 2 weeks before initiating regular dialysis