Baseline characteristics of participants grouped by road distance to hospital (n=22 772)
| Distance between patient home and hospital | |||
| <10 km | 10–30 km | >30 km | |
| n | 12 335 | 8542 | 1895 |
| Age | 67 (51–78) | 69 (55–78) | 69 (56–78) |
| Female (%) | 6155 (49.9) | 4390 (51.4) | 959 (50.6) |
| ASA-PS (%) | |||
| 1 or 2 | 5384 (43.6) | 3704 (43.4) | 810 (42.7) |
| 3 | 3835 (31.1) | 2710 (31.7) | 611 (32.2) |
| 4 | 2731 (22.1) | 1883 (22.0) | 430 (22.7) |
| 5 | 385 (3.1) | 245 (2.9) | 44 (2.3) |
| Malignancy (%) | |||
| None | 10 260 (83.2) | 7038 (82.4) | 1560 (82.3) |
| Primary only | 1057 (8.6) | 746 (8.7) | 177 (9.3) |
| Nodal metastases | 359 (2.9) | 278 (3.3) | 57 (3.0) |
| Distant metastases | 603 (4.9) | 441 (5.2) | 96 (5.1) |
| Missing data | 56 (0.5) | 39 (0.5) | 5 (0.3) |
| ECG signs (%) | |||
| No abnormalities | 9607 (77.9) | 6619 (77.5) | 1447 (76.4) |
| AF rate 60–90 | 460 (3.7) | 312 (3.7) | 87 (4.6) |
| AF rate >90 or other arrhythmia | 2187 (17.7) | 1552 (18.2) | 345 (18.2) |
| Missing data | 81 (0.7) | 59 (0.7) | 16 (0.8) |
| Cardiac signs (%) | |||
| No failure | 9071 (73.5) | 6162 (72.1) | 1349 (71.2) |
| Diuretic, digoxin, antianginal or antihypertensive therapy | 2491 (20.2) | 1834 (21.5) | 407 (21.5) |
| Oedema, warfarin or borderline cardiomegaly | 575 (4.7) | 404 (4.7) | 97 (5.1) |
| Raised JVP or cardiomegaly | 146 (1.2) | 109 (1.3) | 27 (1.4) |
| Missing data | 52 (0.4) | 33 (0.4) | 15 (0.8) |
| Respiratory signs (%) | |||
| No dyspnoea | 8766 (71.1) | 6111 (71.5) | 1326 (70.0) |
| Dyspnoea on exertion or mild COPD | 1982 (16.1) | 1420 (16.6) | 323 (17.0) |
| Limiting dyspnoea or dyspnoea at rest | 1527 (12.4) | 980 (11.5) | 234 (12.3) |
| Missing data | 60 (0.5) | 31 (0.4) | 12 (0.6) |
| Creatinine (mmol/L), median (IQR) | 84 (66–116) | 84 (66–116) | 84 (67–119) |
| Urea (mmol/L), median (IQR) | 7.1 (4.9–10.9) | 7.2 (5.1–11.1) | 7.5 (5.1–11.5) |
| Sodium (mmol/L), median (IQR) | 137 (134–139) | 137 (133–139) | 136 (133–139) |
| Potassium (mmol/L), median (IQR) | 4.1 (3.8–4.5) | 4.2 (3.8–4.5) | 4.1 (3.8–4.5) |
| White cell count (×109/L), median (IQR) | 12.4 (8.7–17.0) | 12.3 (8.6–16.7) | 12.5 (8.8–17.0) |
| Haemoglobin (g/L), median (IQR) | 136 (119–151) | 136 (119–151) | 135 (117–149) |
| Heart rate (BPM), mean (SD) | 95 (20.4) | 95 (20.8) | 95 (21.3) |
| GCS (%) | |||
| 15 | 11 112 (90.1) | 7714 (90.3) | 1699 (89.7) |
| 14 | 705 (5.7) | 467 (5.5) | 115 (6.1) |
| 9–13 | 258 (2.1) | 175 (2.0) | 40 (2.1) |
| 3–8 | 192 (1.6) | 128 (1.5) | 28 (1.5) |
| Missing data | 68 (0.6) | 58 (0.7) | 13 (0.7) |
| Systolic blood pressure (mm Hg), mean (SD) | 124 (25.2) | 124 (25.5) | 124 (26.0) |
| P-POSSUM score, mean (SD) | 21.0 (24.8) | 21.37 (24.7) | 22.46 (25.3) |
| Admission to theatre time (hours), median (IQR) | 11.9 (6.3–22.9) | 12.4 (6.4–23.3) | 12.3 (5.9–23.0) |
| Soiling (%) | |||
| None | 3203 (26.0) | 2311 (27.1) | 514 (27.1) |
| Serous fluid | 3018 (24.5) | 2195 (25.7) | 463 (24.4) |
| Localised pus | 1312 (10.6) | 850 (10.0) | 199 (10.5) |
| Free pus, blood or bowel content | 4735 (38.4) | 3146 (36.8) | 710 (37.5) |
| Missing data | 67 (0.5) | 40 (0.5) | 9 (0.5) |
| Time of hospital admission | |||
| 00:00–03:59 | 1510 (12.2) | 1003 (11.7) | 224 (11.8) |
| 04:00–07:59 | 1228 (10.0) | 867 (10.1) | 182 (9.6) |
| 08:00–11:59 | 2089 (16.9) | 1349 (15.8) | 288 (15.2) |
| 12:00–15:59 | 2742 (22.2) | 1887 (22.1) | 409 (21.6) |
| 16:00–19:59 | 2645 (21.4) | 1906 (22.3) | 413 (21.8) |
| 20:00–23:59 | 2121 (17.2) | 1530 (17.9) | 379 (20.0) |
| IMD quintile (%) | |||
| 1 (least deprived) | 1909 (15.5) | 1957 (22.9) | 259 (13.7) |
| 2 | 1950 (15.8) | 1982 (23.2) | 407 (21.5) |
| 3 | 2053 (16.6) | 1833 (21.5) | 578 (30.5) |
| 4 | 2622 (21.3) | 1460 (17.1) | 359 (18.9) |
| 5 (most deprived) | 3443 (27.9) | 1086 (12.7) | 219 (11.6) |
| Missing data | 358 (2.9) | 224 (2.6) | 73 (3.9) |
| Urgency (%) | |||
| Urgent (2–6 hours) | 8669 (70.3) | 6001 (70.3) | 1344 (70.9) |
| Emergency surgery delayed for resuscitation* | 711 (5.8) | 552 (6.5) | 109 (5.8) |
| Immediate (<2 hours) | 2955 (24.0) | 1989 (23.3) | 442 (23.3) |
| 30-day mortality (%) | 1745 (14.1) | 1186 (13.9) | 293 (15.5) |
| 90-day mortality (%) | 2115 (17.1) | 1475 (17.3) | 350 (18.5) |
*Option previously included in the National Emergency Laparotomy Audit (NELA) data set.
AF, Atrial fibrillation; ASA-PS, American Society of Anesthesiologists physical status classification; BPM, beats per minute; COPD, chronic obstructive pulmonary disease; GCS, Glasgow coma scale; IMD, index of multiple deprivation; JVP, jugular venous pulse; P-POSSUM, Portsmouth physiological and operative severity score for the enumeration of mortality and morbidity.