Supplementary Table 1 — Characteristics of patients included in our study (n = 76) Qualitative variables n (%)
Sex
Male 47 (61.8)
Female 29 (38.2)
Charlson Comorbidity Index*
0 22 (28.9)
1 25 (32.9)
2 14 (18.4)
≥ 3 15 (19.7)
Etiology
Infectious enteritis/colitis† 15 (19.7) Inflammatory bowel disease 11 (14.5) Complicated pancreatitis 7 (9.2) Non-specific colitis 7 (9.2)
Angiodysplasia 6 (7.9)
Diverticulosis 5 (6.6)
Ischemic colitis 5 (6.6)
Unknown 5 (6.6)
Coagulopathy/thrombocytopenia 4 (5.3)
Tumor 4 (5.3)
Trauma‡ 3 (3.9)
Solitary rectal ulcer 2 (2.6)
Stress ulceration 1 (1.3)
Vasculitis 1 (1.3)
Coagulopathy 16 (21.1)
Thrombocytopenia 20 (26.3)
Quantitative variables Values Age (years)
Range 18–92
Mean (standard deviation) 50.9 (18.9) Median (interquartile range) 51 (35–64) Nadir hemoglobin (g/dL)
Range 3.1–8.7
Mean (standard deviation) 6.9 (1.4) Median (interquartile range) 7.3 (6.0–8.0) Packed RBC transfused
Range 13–89
Mean (standard deviation) 32.9 (18.1) Median (interquartile range) 28 (20–40) RBC = red blood cell.
* For details on how the Charlson Comorbidity Index was calculated, please refer to: Charlson M, Szatrowski TP, Peterson J, Gold J. Validation of a combined comorbidity index. J Clin Epidemiol 1994; 47: 1245–51.
† Includes three cases of intestinal tuberculosis and one case of typhoid fever.
‡ Includes one case of iatrogenic (surgical) trauma.
Supplementary Table 2 — Comparison of characteristics of patients who underwent RBC scintigraphy only, MDCT with GI bleed protocol
only, or both modalities in our study
Characteristics Scintigraphy only (n = 51) MDCT only (n = 20) Both modalities (n = 5) p-value Qualitative characteristics — n (%)
Female 21 (41.2) 5 (25) 3 (60) 0.262†
Charlson Comorbidity Index*
0.881†
0 15 (29.4) 6 (30) 1 (20)
1 17 (33.3) 6 (30) 2 (40)
2 8 (15.7) 4 (20) 2 (40)
≥ 3 11 (21.6) 4 (20) 0 (0)
Etiology
0.997†
Infectious enteritis/colitis 10 (19.6) 4 (20) 1 (20)
Inflammatory bowel disease 7 (13.7) 3 (15) 1 (20)
Complicated pancreatitis 4 (7.8) 2 (10) 1 (20)
Non-specific colitis 5 (9.8) 2 (10) 0 (0)
Angiodysplasia 4 (7.8) 1 (5) 1 (20)
Diverticulosis 3 (5.9) 1 (5) 1 (20)
Ischemic colitis 3 (5.9) 2 (10) 0 (0)
Unknown 4 (7.8) 1 (5) 0 (0)
Coagulopathy/thrombocytopenia 3 (5.9) 1 (5) 0 (0)
Tumor 3 (5.9) 1 (5) 0 (0)
Trauma 1 (1.9) 2 (10) 0 (0)
Solitary rectal ulcer 2 (3.9) 0 (0) 0 (0)
Stress ulceration 1 (1.9) 0 (0) 0 (0)
Vasculitis 1 (1.9) 0 (0) 0 (0)
Coagulopathy 11 (21.6) 4 (20) 1 (20) 0.988†
Thrombocytopenia 14 (27.4) 5 (25) 1 (20) 0.926†
Quantitative characteristics
Age (years) 0.919‡
Range 18–92 18–90 25–69
Mean (standard deviation) 51.4 (17.9) 50.3 (22.6) 48 (16)
Median (interquartile range) 51 (36–65) 50 (31–64) 50 (43–53)
Nadir hemoglobin (g/dL)
0.780‡
Range 3.2–8.6 3.1–8.7 5.5–8.5
Mean (standard deviation) 6.9 (1.4) 6.8 (1.5) 7.3 (1.2)
Median (interquartile range) 7.3 (6.1–8.0) 7 (5.9–7.8) 7.7 (6.8–8.0) Packed RBC transfused
0.802‡
Range 13–88 13–89 15–50
Mean (standard deviation) 32.9 (18) 34.1 (19.9) 28 (13.8)
Median (interquartile range) 29 (20–41) 28 (20–40) 23 (20–32)
GI = gastrointestinal; MDCT = multi-detector row computed tomography; RBC = red blood cell.
* For details on how the Charlson Comorbidity Index was calculated, please refer to: Charlson M, Szatrowski TP, Peterson J, Gold J. Validation of a combined comorbidity index. J Clin Epidemiol 1994; 47: 1245–51.
† p-values obtained using Chi-Square (χ2) or Fisher’s exact test.
‡ p-values obtained using one-way analysis of variance (ANOVA) with post-test Bonferroni correction. Barlett test (post-correction) for all comparisons suggested that differences in standard deviation among the three groups were not statistically significant.