Characteristics of patients included in the external validation cohorts
| Inclusion site | Israel (n=148) | Italy (n=3324) | Spain (n=547) | UK (n=2336) |
| Bleeding location | UGIB | UGIB | UGIB | LGIB |
| Patient characteristics | ||||
| Age, median (95% CI) | 69 (30 to 87) | 71 (40 to 89) | 67 (36 to 87) | 73 (29 to 91) |
| Male sex | 94 (64) | 2242 (68) | 367 (67) | 1124 (48) |
| Comorbidities | ||||
| Altered mental status | 13 (8.8) | 519 (17) | 34 (6.2) | 68 (3.1) |
| Liver cirrhosis | 20 (14) | 682 (21) | 141 (26) | 28 (1.2) |
| Disseminated malignancy | 16 (11) | 73 (2.2) | 21 (3.8) | 77 (3.3) |
| ASA score | ||||
| 1 | 18 (12) | 871 (26) | 63 (12) | 687 (30) |
| 2 | 25 (17) | 1148 (35) | 111 (21) | 928 (40) |
| 3 | 87 (59) | 1097 (33) | 298 (55) | 529 (23) |
| 4 | 18 (12) | 207 (6.2) | 68 (13) | 175 (7.6) |
| 5 | 0 (0) | 0 (0) | 1 (0.2) | 0 (0) |
| mean (95% CI) | 2.7 (1 to 4) | 2.2 (1 to 4) | 2.7 (1 to 4) | 2.1 (1 to 4) |
| Blood tests, median (95% CI) | ||||
| Haemoglobin, g/L | 93.5 (54 to 137) | 89 (53 to 139) | 93 (55 to 141) | 124 (69 to 158) |
| Albumin, g/L | 35 (25 to 43) | 32 (22 to 42) | 32 (20 to 42) | 38 (25 to 47) |
| Urea, mmol/L | 25 (9.6 to 65) | 20 (3.9 to 56) | 24 (9.3 to 72) | 6.3 (2.9 to 16.3) |
| Creatinine, µmol/L | 75 (48 to 283) | 88 (53 to 274) | 80 (53 to 265) | 80 (51 to 174) |
| Risk scores, median (95% CI) | ||||
| ABC score | 4 (1 to 11) | 4 (1 to 10) | 5 (1 to 9) | 2 (0 to 7) |
| AIMS65 | 1 (0 to 3) | 1 (0 to 3) | 1 (0 to 3) | 1 (0 to 2) |
| Oakland score | – | – | – | 14 (7–27) |
| AUROCs (95% CI) for mortality | ||||
| ABC score | 0.91 (0.83 to 0.99) | 0.80 (0.77 to 0.83) | 0.81 (0.76 to 0.86) | 0.84 (0.80 to 0.89) |
| AIMS65 | 0.83 (0.70 to 0.95) | 0.62 (0.58 to 0.65) | 0.75 (0.69 to 0.81) | 0.75 (0.68 to 0.83) |
| Oakland score | – | – | – | 0.69 (0.61 to 0.77) |
| Mortality* | 6 (4.1) | 223 (6.7) | 51 (9.6) | 52 (2.3) |
Numbers are n(%) unless otherwise stated. Missing data in UGIB-validation cohorts: ABC score (n=593), AIMS65 (n=972), age (n=25), sex (n=20), albumin (n=378), haemoglobin (n=14), blood urea nitrogen (n=183), creatinine (n=163), altered mental status (n=770), liver cirrhosis (n=548), disseminated malignancy (n=547), ASA-score (n=7), and mortality (n=18). Missing data in LGIB-validation cohort: ABC score (n=552), AIMS65 (n=718), Oakland score (n=707), age (n=1), sex (n=10), albumin (n=393), haemoglobin (n=17), urea (n=71), creatinine (n=45), altered mental status (n=142), liver cirrhosis (n=10), disseminated malignancy (n=10), ASA-score (n=20), and mortality (n=35).
*Noted mortality rates reflect 30 day mortality in patients with UGIB and in-hospital mortality in patients with LGIB (see methods).
ABC, age, blood tests and comorbidities; ASA, American Society of Anesthesiologists; AUROC, area under receiving operator characteristics curves; LGIB, lower gastrointestinal bleeding; UGIB, upper gastrointestinal bleeding.