Table 2.

Criteria for site selection

A. General criteria for all sites	Judgment standard
1. Number of MT patients reported in the retrospective study	Multiple of the median number of MT patients among 22 sites
2. Diverse range of platelet:PRBC ratios among MT patients	Multiple of the median interquartile range among sites
3. Diverse range of mean plasma:PRBC ratios among MT patients
4. Site management/compliance with retrospective protocol, deliverables and timeline based on the cumulative site monitoring documentation at the end of the retrospective study	One point if expectations were met
5. Is an NIH/NCRR-funded CTSA Consortium Member?	One point if yes
6. Experience in performing clinical studies of massively transfused (MT) trauma patients that includes the use of blood samples collected at ED admission for research laboratory studies
7. Experience in changing transfusion practice guidelines (since 2006) to increase plasma:platelet:PRBC ratios
8. Is a member of the NIH/NHLBI-DoD-funded Resuscitation Outcomes Consortium (ROC)?
9. Is a priority site based on the experience of the PI of retrospective study?	One point if first priority, 0.5 if second priority
Total individual score = sum of points on 9 criteria
B. Criteria for candidate group of 10 sites (of 646,646 possible combinations of 10 sites)
1. Diverse range of 24 hour mortality rates among sites	Interquartile range among the 10 sites within the group/interquartile range among 22 sites
2. Diverse range of platelet:PRBC ratios across sites
3. Diverse range of plasma:PRBC ratios across sites
4. Diverse geographic representation	One point if all 4 US regions (N, S, E, W) are represented among the 10 sites within the group, 0.75 points if only 3 regions are represented
Total group score = sum of points on 4 criteria