Differences in Performance of Bayesian Dynamic Borrowing and Synthetic Control Methods: A Case Study of Pediatric Atopic Dermatitis

Bayesian dynamic borrowing (BDB) and synthetic control methods (SCM) are both used in clinical trial design when recruitment, retention, or allocation is a challenge. The performance of these approaches has not previously been directly compared due to differences in application, product, and measurement metrics. This study aims to conduct a comparison of power and type 1 error rates of BDB (using meta-analytic predictive prior (MAP)) and SCM using a case study of Pediatric Atopic Dermatitis. Six historical randomised control trials were selected for use in both the creation of the MAP prior and synthetic control arm. The R library RBesT was used to create a MAP prior and the R library Synthpop was used to create a synthetic control arm for the SCM. Power and type 1 error rate were used as comparison metrics. BDB produced a power of 0.580 and a type 1 error rate of 0.026. SCM produced a power of 0.641 and a type 1 error rate of 0.027. In this case study, the SCM model produced a higher power than the BDB method with a similar type 1 error rate. However, the decision to use SCM or BDB should come from the specific needs of the potential trial, since their power and type 1 error rate may differ on a case-by-case basis.