Abo Blood Types and Mortality Following Critical Illness: A Single Centre Retrospective Observational Study

INTRODUCTION: It is challenging to predict patient outcomes following critical illness. Recent evidence from UK has suggested that patients with blood group AB appeared to have higher 90-day survival compared with other blood groups after a critical illness(1). However, there are no current data to substantiate this finding in Asian population. OBJECTIVES: The objective of this study was to determine if ABO blood group affects survival in intensive care. The primary outcome of this study was to measure 30-day mortality. MATERIALS AND METHODS: This is a single centre retrospective study conducted in ICU of a teritiary care hospital with both medical and surgical patients. All patients admitted to ICU between January 2023 to November 2024 were included in the study. RESULTS: 940 patients were included in this study, blood group AB accounted for 6.3% (60), A 18.9% (178), B 35.31% (332), O 39.3% (370). These values differ from Indian averages (O-48%, A- 38%, B-10%, AB- 3%). Mortality in patients with different blood group following a critical illness is A(25.8%), B(31.9%), O(35.5%), AB(20%). Survival proportion for each blood group were A - 78.7, B - 78.9, O – 73.5, AB – 80 (log-rank χ2 4.4489, p=0.216). Though we observed a Slight survival benefit with AB blood group, overall there is no statistically significant difference. CONCLUSIONS: In our study, patients with AB blood group had a slight survival benefit when compared to patients with other blood groups following critical illness. This survival benefit did not reach statistical significance.