Inform Trial : No effect of blood storage time on mortality after transfusion

Inform trial results were published in NEJM on Oct 24, 2016.

31,497 adult patients  at six hospitals in four countries (Australia, Canada, Israel and the U.S) were randomized to receive short or long term stored blood. There was no difference in mortality among two groups.

Earlier, a meta analysis of 12 randomized trials showed no difference in 90 day mortality between fresh and standard stored blood in critically ill patients.

Salient points

  1. Mean storage duration was 13.0 days in the shortterm storage group and 23.6 days in the longterm storage group.
  2. Patients received blood that was stored for the shortest duration (shortterm storage group) or the longest duration (longterm storage group) in a 1:2 ratio.
  3. Following patients were excluded A. If they were expected to receive a massive transfusion, B. Required blood that had not been cross-matched, C. Required autologous or directed transfusion, D. Had an indication for fresh-only red-cell transfusion. E. Some patients with alloimmunity to red-cell antigens.
  4. US center did not enroll patients undergoing cardiac surgery. Canadian center did not enroll patients from ICU.
  5. Primary analysis was only done on patients with blood group A or O. However, secondary analysis did include other groups and was similar.
  6. Subgroup analysis in patients having cardiovascular surgery, admitted to the intensive care unit or patients with cancer showed no difference.

RS