Table 1.
Characteristics of hospitalisations identified in the DNRP from 2006 to 2011
| Hospitalisations with at least on serum sodium value <135 mmol/L recorded in the LABKA research database |
All hospitalisations (n=2 186 642), n (%) | ||
|---|---|---|---|
| ICD-10 code of hyponatraemia in the DNRP (n=5410), n (%) | No ICD-10 code of hyponatraemia in the DNRP* (n=301 008), n (%) | ||
| Sex | |||
| Female | 3643 (67.3) | 148 120 (49.3) | 1 168 803 (53.5) |
| Male | 1767 (32.7) | 152 588 (50.7) | 1 017 839 (46.5) |
| Age, years | |||
| Median (IQR) | 77.3 (65.7–84.9) | 67.4 (54.2–78.2) | 54.7 (29.3–71.1) |
| Department of admission | |||
| Internal medicine | 5173 (95.6) | 184 848 (61.6) | 943 121 (43.1) |
| Surgical | 184 (3.4) | 88 378 (29.4) | 630 525 (28.8) |
| Gynaecological/obstetric | 10 (0.2) | 7104 (2.4) | 347 365 (15.9) |
| Paediatric | 29 (0.5) | 15 830 (5.3) | 165 289 (7.6) |
| Other | 14 (0.3) | 4848 (1.6) | 100 342 (4.6) |
| CCI level (score) | |||
| Low (0) | 2075 (38.4) | 100 398 (33.4) | 1 232 762 (56.4) |
| Medium (1–2) | 2182 (40.3) | 106 874 (35.5) | 588 783 (26.9) |
| High (≥3) | 1153 (21.3) | 93 736 (31.1) | 365 097 (16.7) |
| Specific comorbidities | |||
| Myocardial infarction | 312 (5.8) | 23 269 (7.7) | 108 373 (5.0) |
| Congestive heart failure | 460 (8.5) | 31 236 (10.4) | 121 429 (5.6) |
| Peripheral vascular disease | 464 (8.6) | 29 356 (9.8) | 115 620 (5.3) |
| Cerebrovascular disease | 1017 (18.8) | 39 466 (13.1) | 182 304 (8.3) |
| Dementia | 107 (3.1) | 4247 (1.4) | 20 711 (1.0) |
| Chronic pulmonary disease | 870 (16.1) | 48 726 (16.2) | 231 121 (10.6) |
| Connective tissue disease | 291 (5.4) | 13 990 (4.7) | 73 299 (3.4) |
| Ulcer disease | 450 (8.3) | 20 645 (6.9) | 79 050 (3.6) |
| Mild liver disease | 189 (3.5) | 13 413 (4.5) | 37 698 (1.7) |
| Moderate-to-severe liver disease | 66 (1.2) | 6279 (2.1) | 14 999 (0.7) |
| Diabetes I and II | 521 (9.6) | 39 995 (13.3) | 150 205 (6.9) |
| Diabetes with complications | 269 (5.0) | 25 083 (8.3) | 85 035 (3.9) |
| Hemiplegia | 35 (0.7) | 2462 (0.8) | 16 060 (0.7) |
| Moderate-to-severe renal disease | 143 (2.6) | 20 123 (6.7) | 75 441 (3.5) |
| Malignant tumour | 781 (14.4) | 64 882 (21.6) | 312 845 (14.3) |
| Leukaemia | 22 (0.4) | 4636 (1.5) | 17 190 (0.8) |
| Lymphoma | 51 (0.9) | 7096 (2.4) | 25 348 (1.2) |
| Metastatic cancer | 183 (3.4) | 23 948 (8.0) | 105 512 (4.8) |
| AIDS | 3 (0.1) | 475 (0.2) | 2014 (0.1) |
CCI, Charlson Comorbidity Index; DNRP, Danish National Registry of Patients; ICD-10, International Classification of Diseases, 10th revision.