Table 1.
The baseline characteristics of the patients stratified by their number of rare diseases
| Number of rare diseases per patient | 0 | 1 | > 1 |
|---|---|---|---|
| Number of patients per group | 146,804 | 17,051 | 2053 |
| Demographics | |||
| Age groups (%) | |||
| 18–34 | 36,084 (24.6) | 2280 (13.4) | 291 (14.2) |
| 35–49 | 32,924 (22.4) | 2905 (17.0) | 382 (18.6) |
| 50–64 | 31,883 (21.7) | 4679 (27.4) | 593 (28.9) |
| 65–79 | 31,417 (21.4) | 5160 (30.3) | 615 (30.0) |
| 80 and older | 14,496 (9.9) | 2027 (11.9) | 172 (8.4) |
| Sex = M (%) | 67,557 (46.0) | 9437 (55.3) | 1179 (57.4) |
| Diagnosis count, excluding rare diseases (median [IQR]) | 4.00 [2.00, 7.00] | 5.00 [3.00, 9.00] | 8.00 [4.00, 13.00] |
| Rare diseases | |||
| Certain infectious and parasitic diseases (%) | 0 (0.0) | 516 (3.0) | 192 (9.4) |
| Neoplasms (%) | 0 (0.0) | 3035 (17.8) | 590 (28.7) |
| Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (%) | 0 (0.0) | 609 (3.6) | 159 (7.7) |
| Endocrine nutritional and metabolic diseases (%) | 0 (0.0) | 1772 (10.4) | 467 (22.7) |
| Mental and behavioural disorders (%) | 0 (0.0) | 22 (0.1) | 6 (0.3) |
| Diseases of the nervous system (%) | 0 (0.0) | 3357 (19.7) | 574 (28.0) |
| Diseases of the eye and adnexa (%) | 0 (0.0) | 401 (2.4) | 49 (2.4) |
| Diseases of the ear and mastoid process (%) | 0 (0.0) | 169 (1.0) | 30 (1.5) |
| Diseases of the circulatory system (%) | 0 (0.0) | 1551 (9.1) | 393 (19.1) |
| Diseases of the respiratory system (%) | 0 (0.0) | 210 (1.2) | 57 (2.8) |
| Diseases of the digestive system (%) | 0 (0.0) | 655 (3.8) | 234 (11.4) |
| Diseases of the skin and subcutaneous tissue (%) | 0 (0.0) | 307 (1.8) | 56 (2.7) |
| Diseases of the musculoskeletal system and connective tissue (%) | 0 (0.0) | 1659 (9.7) | 280 (13.6) |
| Diseases of the genitourinary system (%) | 0 (0.0) | 78 (0.5) | 4 (0.2) |
| Pregnancy childbirth and the puerperium (%) | 0 (0.0) | 167 (1.0) | 6 (0.3) |
| Congenital malformations, deformations and chromosomal abnormalities (%) | 0 (0.0) | 1958 (11.5) | 460 (22.4) |
| Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (%) | 0 (0.0) | 585 (3.4) | 162 (7.9) |
| Outcomes | |||
| Number of patients who died in hospital (%) | 3202 (2.2) | 1082 (6.3) | 262 (12.8) |
| 30-day readmission (%) | |||
| No | 137,918 (93.9) | 15,364 (90.1) | 1819 (88.6) |
| Unknown | 1768 (1.2) | 215 (1.3) | 29 (1.4) |
| Yes | 7118 (4.8) | 1472 (8.6) | 205 (10.0) |
| Length of stay in days (median [IQR]) | 5.00 [3.00, 8.00] | 7.00 [4.00, 14.00] | 11.00 [5.00, 20.00] |
| ICU admissions (%) | 16,178 (11.0) | 3987 (23.4) | 763 (37.2) |
| Total time spent in ICUs in days (median [IQR]) | 0.00 [0.00, 0.00] | 0.00 [0.00, 0.00] | 0.00 [0.00, 2.00] |
| Total time spent in ICUs in days (mean (SD)) | 0.44 (2.70) | 1.45 (5.63) | 3.59 (9.39) |
All p-values < 0.001