BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250508T120658EDT-0759iudUh7@132.216.98.100 DTSTAMP:20250508T160658Z DESCRIPTION:Shu Yang\, PhD\n\nAssociate Professor\n Department of Statistics |\n NC State University\n\nWHEN: Wednesday\, November 6\, 2024\, from 3:30 to 4:30 p.m.\n WHERE: Hybrid | 2001 ºÃÉ«TVl College Avenue\, Room 1201\; Zo om\n NOTE: Shu Yang will be presenting from North Carolina\n\nAbstract\n\nR andomized controlled trials (RCTs) are the gold standard for causal infere nce on treatment effects\, but they can be limited by small sample sizes d ue to the indications associated with rare diseases and small patient popu lations\, where ethical concerns or patient reluctance may limit control g roup assignment. Hybrid controlled trials use external controls (ECs) from historical studies or large observational databases to enhance statistica l efficiency. However\, non-randomized ECs can introduce biases that compr omise validity and inflate Type I errors for treatment discovery\, particu larly in small samples. To address this\, we extend the Fisher randomizati on test to hybrid controlled trials. Our approach involves a test statisti c combining RCT and EC data and is based solely on randomization in the RC T. This method strictly controls the Type I error rate\, even with biased ECs\, and improves power by incorporating unbiased ECs.\n \n To mitigate the power loss caused by biased ECs\, we introduce Conformal Selective Borrow ing\, which uses individual conformal p-values to selectively incorporate unbiased ECs\, offering the flexibility to use either computationally effi cient parametric models or off-the-shelf machine learning models to constr uct the score function\, along with model-agnostic reliability. We identif y a risk-benefit trade-off in the power of FRT\, associated with different selection thresholds for conformal p-values\, analogous to the mean squar ed error trade-offs observed in the data integrative estimators. We propos e a data-driven selection of the threshold value to achieve robust perform ance across different levels of hidden bias. The advantages of our method are demonstrated through simulations and an application to a small-sized l ung cancer trial with ECs from the National Cancer Database.\n\nSpeaker bi o\n\nShu Yang is Associate Professor of Statistics at North Carolina State University. She received her Ph.D. in Applied Mathematics and Statistics from Iowa State University and postdoctoral training at Harvard T.H. Chan School of Public Health. Her primary research interest is causal inference and data integration\, particularly with applications to comparative effe ctiveness research in health studies. She also works extensively on method s for missing data and spatial statistics. She has been Principal Investig ator for several U.S. NSF\, NIH\, and FDA research projects. For more info rmation\, please visit https://shuyang.wordpress.ncsu.edu/.\n DTSTART:20241106T203000Z DTEND:20241106T213000Z SUMMARY:Enhancing Statistical Validity and Power in Hybrid Controlled Trial s: A Randomization Inference Approach with Conformal Selective Borrowing URL:/epi-biostat-occh/channels/event/enhancing-statist ical-validity-and-power-hybrid-controlled-trials-randomization-inference-a pproach-360430 END:VEVENT END:VCALENDAR