Keywords: Study Enrollment, Site Enrollment, Enrollment Cap, Statistical Enrollment Balance
Room: Marriott Balcony B
There is one metric that every statistician should consider at the beginning stages of any multicenter clinical trial: the site enrollment cap. Determining a feasible site cap early on helps ensure that one individual site does not contribute too many subjects to the trial. Lack of early consideration of maximum site enrollment causes a higher chance of site enrollment disparities as the study comes to a close and the problem becomes permanent. Multicenter studies often require poolability across sites which is dependent on comparable enrollment counts for statistical validity. Based on total patient count, how many sites can be considered for enrollment without compromising enrollment balance and subsequent comparability? What considerations need to be given to determine the enrollment cap for each site? Will each site be capped at the same value or will it vary? Will there be tiered enrollment where sites can get approval to go to the next enrollment level (e.g. low enroller, mid enroller, high enroller)? It is essential that a good statistician find balance between allowing high enrolling sites to “do their thing” while still achieving appropriate balance across all sites. The purpose of this roundtable is to discuss the statistical considerations and challenges a statistician may face in providing guidance on these questions during study conduct.