AIMS65, Glasgow-Blatchford bleeding score and modified Glasgow-Blatchford bleeding score in predicting outcomes of upper gastrointestinal bleeding: An accuracy and calibration study

Background: Albumin, international normalized ratio (INR), mental status, systolic blood pressure, age >65 years (AIMS65), Glasgow-Blatchford bleeding score (GBS) and modified GBS (mGBS) are three pre-endoscopy scoring systems used in the risk stratification of upper gastrointestinal bleeding (UGIB). The utility of such scoring systems in a population is estimated by their accuracy and calibration in the population. We aimed at validating and comparing the accuracy of the three scoring systems in predicting clinical outcomes including in-hospital mortality, need for blood transfusion, endoscopic treatment and rebleeding risk.

Method: We conducted a single-center, retrospective cohort study on patients with UGIB at a tertiary care center in India over 12 months. Clinical and laboratory data was collected from all patients admitted with UGIB. All patients were risk stratified using AIMS65, GBS and mGBS. The clinical outcome examined were: in-hospital mortality, requirement of blood transfusion, need for endoscopic treatment and rebleeding during hospital stay. The area under receiver-operating curve (AUROC) was calculated to assess the performance and calibration curves (Hosmer-Lemeshow goodness of fit curve) were plotted to examine how accurately the model describes the data of all three scoring systems.

Results: Total 260 patients were included in the study, of which 236 (90.8%) were males. As many as 144 (55.4%) patients required blood transfusion and 64 (30.8%) required endoscopic treatment. While the incidence of rebleeding was 7.7%, in hospital mortality was 15.4%. Of 208 who underwent endoscopy, the most common causes identified were varices (49%) and gastritis (18.2%), followed by ulcer (11%), Mallory-Weiss tear (8.1%), portal hypertensive gastropathy (6.7%), malignancy (4.8%) and esophageal candidiasis (1.9%). The median AIMS65 score was 1, GBS 7 and mGBS 6. The area under curve (AUROC) for AIMS65, GBS and mGBS was (0.77, 0.73,0.70), (0.75, 0.82,0.83), (0.56, 0.58,0.83), (0.81, 0.94,0.53) for in-hospital mortality, blood transfusion requirement, endoscopic treatment and rebleeding prediction, respectively.

Conclusion: GBS and mGBS are superior to AIMS65 in predicting the requirement of blood transfusion and rebleeding risk, whereas in-hospital mortality was better predicted by AIMS 65. Both scores performed poorly in predicting the need of endoscopic treatment. An AIMS65 of 0,1 and a GBS of ≤ 1 are not associated with significant adverse events. A poor calibration of the scores in our population points to the lack of generalizability of these scoring systems.