MedicalResearch.com Interview with: Märit Halmin, MD, PhD student Department of Medical Epidemiology and Biostatistics, Karolinska Institutet,  Stockholm, Sweden MedicalResearch.com: What is the background for this study? Response: During recent years the possible negative effects among recipients of stored red blood cells have been investigated.  Despite a large number of studies, including four randomized trials, no consensus exists. We therefore performed the hitherto largest register based cohort study of transfused patients, assessing the association between length of storage of red blood cells and mortality. Our design allowed for detection of small but still clinically significant effect, if such exists. (more…)