Univariate analysis
| Variable | Discharged and not readmitted to hospital within 30 days (n=7675) | Readmitted to hospital within 30 days (n=2691) | Significance |
| Gender | p=0.03* | ||
| Male (%) | 3548 (46.25) | 1308 (48.64) | |
| Female (%) (available in 10 360) | 4123 (53.75) | 1381 (51.63) | |
| LOS | |||
| Median (IQR) | 5 (9) | 6 (10) | p<0.001* |
| Age | |||
| Median (IQR) | 75 (21) | 75 (18) | p>0.999* |
| CURB-65 score 3–5 | 1405 (18.30) | 414 (15.38) | p=0.0007* |
| Chronic kidney disease | |||
| Absent | 6680 (87.04) | 2263 (84.10) | p=0.0002* |
| Present | 995 (12.96) | 428 (15.90) | |
| Dementia | |||
| Absent | 7185 (93.62) | 2558 (95.06) | p=0.008* |
| Present | 490 (6.38) | 133 (4.84) | |
| Liver disease | |||
| Absent | 7615 (98.22) | 2666 (99.07) | p=0.54* |
| Present | 60 (0.78) | 25 (0.93) | |
| Cardiac failure | |||
| Absent | 6610 (86.13) | 2241 (83.28) | p=0.0004* |
| Present | 1065 (13.87) | 450 (16.72) | |
| Non-metastatic.cancer | |||
| Absent | 6932 (90.32) | 2253 (83.72) | p<0.0001* |
| Present | 743 (9.68) | 438 (16.28) | |
| COPD | |||
| Absent | 5219 (68.1) | 1725 (64.10) | p=0.0002* |
| Present | 2456 (31.9) | 966 (35.90) | |
| Ischaemic heart disease | |||
| Absent | 6842 (89.15) | 2347 (87.22) | p=0.007* |
| Present | 833 (10. 85) | 344 (12.78) | |
| Mental health | |||
| Absent | 6958 (90.66) | 2421 (89.97) | p=0.31* |
| Present | 717 (9.34) | 270 (10.03) | |
| Severe liver disease | |||
| Absent | 7657 (9977) | 2681 (99.63) | p=0.06* |
| Present | 18 (0.23) | 10 (0.37) | |
| Stroke | |||
| Absent | 7397 (96.38) | 2588 (96.17) | p=0.32* |
| Present | 278 (3.62) | 103 (3.83) | |
| Pulmonary disease | |||
| Absent | 6177 (80.48) | 2135 (79.34) | p=0.21* |
| Present | 1498 (19.52) | 556 (20.66) | |
| Diabetes mellitus | |||
| Absent | 6243 (81.34) | 2130 (79.15) | p=.0.01* |
| Present | 1432 (18.66) | 561 (20. 85) | |
| Myocardial infarction | |||
| Absent | 7611 (99.17) | 2668 (99.15) | p=0.92* |
| Present | 64 (0.83) | 23 (0.85) | |
| Diabetes complications | |||
| Absent | 7607 (99.11) | 2652 (98.55) | p=0.02* |
| Present | 68 (0.89) | 39 (1.45) | |
| Renal disease | |||
| Absent | 7658 (99.78) | 2688 (99.89) | p=0.39* |
| Present | 17 (0.22) | 3 (0.11) | |
| Metastatic cancer | |||
| Absent | 7417 (96.64) | 2533 (94.13) | p=0.0001* |
| Present | 258 (3.36) | 158 (5.87) | |
| Learning disability | |||
| Absent | 7573 (98.67) | 2651 (98.51) | p=0.59* |
| Present | 102 (1.33) | 40 (1.49) | |
| Previous admissions in 12 months prior to index admission; median (IQR) | 2 (4) | 1 (2) | p<0.0001† |
*Independent samples t-test.
†Mann-Whitney U test.
COPD, chronic obstructive pulmonary disease; LOS, length of stay.