The article, "Intraosseous versus intravenous vascular access in the upper extremity in adults with out-of-hospital cardiac arrest: a cluster randomized clinical trial (VICTOR trial)" (doi:10.1136/bmj-2024-079878) has been retracted from the journal BMJ. After publication, online commentary raised concerns about the randomization scheme and allocation ratio in this cluster randomized trial. There were discrepancies in the original data set for the cluster periods that were inconsistent with patient allocation. The journal's investigation confirmed doubts about the random assignment of patients. There were a large number of patient exclusions that affected the allocation balance (see online supplementary material 1). The article is retracted due to problems with randomization and allocation. The findings and conclusions of the study are therefore unreliable.