Impact of the Clinical Trials Act 2018 on clinical trial activity in Japan from 2018 to 2020: a retrospective database study using new and conventional Japanese registries.

The implementation of the CTA has not reduced the number of specified clinical trials, but has reduced the total number of intervention trials. The use of designated staff in multidisciplinary roles is associated with funding, secondary sponsors and multicentre studies. It was inferred that funding was needed to establish research infrastructure systems that support high-quality research.