Chen, Sheauchiann, Chen, Heidi C., Paez, Rafael, Gatto, Cheryl L., Lentz, Robert James, & Maldonado, Fabien. (2025). A randomization strategy for a cluster-randomized controlled trial with variable operating room availability. Contemporary Clinical Trials, 157, 108057. https://doi.org/10.1016/j.cct.2025.108057
This study compared the clinical outcomes of two bronchoscopy platforms, Platform A and Platform B, using a single-center, open-label, pragmatic, non-inferiority trial. Instead of randomizing individual patients, the trial assigned platforms by operating room (OR) days, since there were limited ORs and only one of each platform available at a time. To ensure a fair distribution of patients between the two platforms, the team tested different randomization strategies using computer simulations. They found that a permuted-block randomization method, which grouped assignments by weekday, improved balance in patient numbers between the platforms. An even better approach was achieved by stratifying assignments based on OR availability, which further reduced differences in the number of patients assigned to each platform. This innovative trial design helped optimize the use of available resources while maintaining fair and balanced comparison between the two bronchoscopy platforms.
Fig. 1. Toy examples for illustrating randomization sheets: A. without stratification. B. stratified by days of the week. C. stratified by room availability.