However, according to the subsequent analysis of the TRICC study data (41) variations in mortality rate after thirty days were found and opposite in the "liberal" group when compared to the mortality rate in the "restrictive" group, according to the presence or absence of coronary artery disease before randomization.
This analysis seems to demonstrate that the results of TRICC may be strongly influenced by the presence of non-comparable groups with different transfusion practices and are inadequate in each study group.
Given that the studies published before the TRICC indicated that clinicians used higher transfusion thresholds in patients with ischemic heart disease than in younger subjects with less comorbidity, none of the study groups represents the usual practice.
In a 1999 study of transfusion requirements in critical care (TRICC) conducted by the Canadian Critical Care Trials Group, patients in ICUs were randomized to 1 of 2 transfusion groups: liberal (transfusion when hemoglobin level was <100 g/L to a target of 100-120 g/L) or restricted (transfusion when hemoglobin was <70 g/L, target 70-90 g/L).
Support for the avoidance of a numerical "transfusion trigger" can be found in the results of the TRICC trial, with its findings of either equivalence or, in some groups, better outcomes when a restrictive transfusion strategy was used.
Data from the TRICC trial, in contrast, failed to support such a conclusion.