Sufficiency of Japan's Future Public Databases in Capturing Data Items for Clinical Trials

This study aimed to evaluate the extent to which the data items required in ongoing prospective clinical trials are available in real-world data (RWD) infrastructures currently being prepared in Japan, with a focus on the availability of trial-level items.

Data items pertaining to target diseases, inclusion or exclusion criteria, and primary endpoints were extracted from phase III clinical trials initiated in Japan (including multiregional clinical trials) in 2022, and then categorized by data items. For each category, the availability of items from the shared electronic medical records data and National Database data was assessed. Subsequently, the availability of data corresponding to the target disease, inclusion or exclusion criteria, and primary endpoints was assessed at a trial level. Additionally, the clinical laboratory values used in the inclusion/exclusion criteria and primary endpoints were evaluated.

Among the 165 target trials, the target disease was identifiable in 158 trials (95.8%); 1,763 of 2,774 inclusion/exclusion criteria items (63.6%), and 47 of 250 primary endpoint items (18.8%) were available. When the predefined criteria for item-level data availability were jointly applied across target diseases, inclusion/exclusion criteria, and primary endpoints, only eight trials (4.8%) met all the conditions.

These findings indicate a substantial gap between the trial-level data requirements for recent phase III clinical trials and the data elements currently planned in Japan's emerging RWD infrastructure. As this initiative is in its early stages in Japan and further improvements are planned, future progress is expected.