Characteristics and outcomes of index admissions to hospital used in the analysis of hospital readmission
| Variable† | Discharge status of index admission, no. (%)* | p value‡ | |
|---|---|---|---|
| AMA n = 21 417 | Non-AMA n = 1 894 687 | ||
| Any AMA discharges in previous 5 yr | 5 076 (23.7) | 42 537 (2.3) | < 0.001 |
| No. of admissions to hospital in previous 5 yr, mean ± SD | 3.8 (6.4) | 2.3 (4.0) | < 0.001 |
| Median (IQR) | 2 (1–4) | 1 (0–3) | < 0.001 |
| Age, yr, mean ± SD | 42.7 (18.0) | 54.1 (22.2) | < 0.001 |
| Male sex | 10 789 (50.4) | 708 491 (37.4) | < 0.001 |
| Average household income quintile | |||
| Urban 1 (lowest urban stratum) | 5 831 (27.2) | 257 035 (13.6) | < 0.001 |
| Urban 3 | 1 557 (7.3) | 185 133 (9.8) | |
| Urban 5 (highest urban stratum) | 598 (2.8) | 132 683 (7.0) | |
| Rural 1 (lowest rural stratum) | 3 864 (18.0) | 227 971 (12.0) | |
| Rural 3 | 1 534 (7.2) | 194 665 (10.3) | |
| Rural 5 (highest rural stratum) | 1 058 (4.9) | 123 465 (6.5) | |
| Not calculated | 272 (1.3) | 47 764 (2.5) | |
| Comorbid conditions | |||
| Alcohol abuse | 6 010 (28.1) | 74 756 (4.0) | < 0.001 |
| Diabetes | 3 341 (15.6) | 227 715 (12.0) | < 0.001 |
| Drug abuse | 2 397 (11.2) | 26 671 (1.4) | < 0.001 |
| Hypertension, uncomplicated | 1 888 (8.8) | 249 682 (13.2) | < 0.001 |
| Chronic pulmonary disease | 1 863 (8.7) | 174 216 (9.2) | 0.01 |
| Congestive heart failure | 1 431 (6.7) | 176 893 (9.3) | < 0.001 |
| Arrythmia | 1 041 (4.9) | 156 032 (8.2) | < 0.001 |
| Liver disease | 1 014 (4.7) | 23 001 (1.2) | < 0.001 |
| Renal failure | 775 (3.6) | 59 475 (3.1) | < 0.001 |
| Hypertension, complicated | 433 (2.0) | 33 177 (1.8) | 0.003 |
| Obesity | 380 (1.8) | 28 665 (1.5) | 0.002 |
| Solid tumour without metastasis | 346 (1.6) | 86 236 (4.6) | < 0.001 |
| Hypothyroidism | 264 (1.2) | 42 992 (2.3) | < 0.001 |
| Metastatic cancer | 254 (1.2) | 63 205 (3.3) | < 0.001 |
| AIDS/HIV | 112 (0.5) | 1 264 (0.1) | < 0.001 |
| Lymphoma | 79 (0.4) | 14 152 (0.8) | < 0.001 |
| Main diagnosis at index admission | |||
| Mental disorder | 4 645 (21.7) | 102 472 (5.4) | < 0.001 |
| Injury or poisoning | 2 862 (13.4) | 140 146 (7.4) | |
| Complication of pregnancy, childbirth or puerperium | 2 227 (10.4) | 353 508 (18.7) | |
| Disease of the digestive system | 2 196 (10.3) | 215 699 (11.4) | |
| Cardiovascular disorder | 1 921 (9.0) | 249 211 (13.2) | |
| Disease of the respiratory system | 1 445 (6.7) | 137 430 (7.3) | |
| Disease of the musculoskeletal system and connective tissue | 607 (2.8) | 91 314 (4.8) | |
| Neoplasm | 358 (1.7) | 118 334 (6.3) | |
| Disease of nervous system or sense organs | 332 (1.6) | 41 305 (2.2) | |
| Infectious or parasitic disease | 311 (1.5) | 19 007 (1.0) | |
| Disease of blood and blood-forming organs | 129 (0.6) | 13 462 (0.7) | |
| Length of index admission, d, median (IQR) | 3 (2–6) | 5 (3–9) | < 0.001 |
| Deaths within indicated intervals after discharge, d§ | |||
| 7 | 97 (0.5) | 6 956 (0.4) | 0.05 |
| 14 | 165 (0.8) | 13 145 (0.7) | 0.2 |
| 30 | 328 (1.5) | 26 600 (1.4) | 0.1 |
| 90 | 739 (3.5) | 67 860 (3.6) | 0.3 |
| 180 | 1 167 (5.5) | 111 171 (5.9) | 0.001 |
Note: AMA = left hospital against medical advice, IQR = interquartile range, non-AMA = did not leave hospital against medical advice, SD = standard deviation.
↵* Unless otherwise indicated.
↵† Only selected variables are shown; see Appendix 2 for full results.
↵‡ χ2 test.
↵§ These are not true death rates, because the unit of measure for this analysis was admissions, not patients.