Journal of Biometrics & Biostatistics

Dynamic Registration Method with Balancing for Prognostic Factors in Observational Studies

Abstract

Masahiro Sugihara, Satoshi Morita, Naoki Yamanouchi, Shinya Sakai, Noriaki Ohba, Wataru Ichikawa and Yasuo Ohashi

 Randomized controlled trials are the most scientifically informative studies for evaluating treatment effects. However, we need to conduct observational studies to evaluate unallocatable factors such as genotype, preference, or lifestyle. In observational studies, subject characteristics among the comparison groups might be imbalanced due to non-random allocation. We proposed a dynamic registration method to improve comparability among comparison groups with no allocation. The dynamic registration method is a registration method based on the minimization method, which decides whether or not to register a subject based on the background information of subjects already recruited and the new subject. Simulation studies were conducted to examine the performance of this method in improving comparability among comparison groups. Simulation studies showed that the dynamic registration method improves the comparability among comparison groups. The dynamic registration method can be used to enhance the quality of observational studies for unallocatable factors.