Objectives:

With real-world data (RWD) being increasingly used to generate real-world evidence (RWE) related to medication safety and effectiveness, this research aims to compare the RWD sources that are available in Japan.

Methods:

Available sources of RWD in Japan (through September 2020) were identified from a targeted literature review and institutional knowledge. Administrative claims and electronic medical records (EMR) data were included; databases containing survey or registry data were excluded, as they may be highly specialized and less generalizable to the overall population. Characteristics of data available in the selected sources and their limitations were summarized descriptively.

Results:

A total of 20 RWD sources were identified. The majority (60%) of these sources were claims databases, 20% linked both claims and EMR, and 20% were EMR. Half (50%) include inpatient, medication, and laboratory data, 25% also included outpatient data, and 25% included only medication data. The majority (75%) of these databases allow industry-sponsored researchers to access the data, whereas the remainder can only be accessed through academic institutions. Importantly, Medical Data Vision (MDV) and Japan Medical Data Center (JMDC) databases have been widely used in the context of industry-sponsored studies, especially for cost analyses. Limitations of identified databases include access restrictions, the potential for loss to follow-up when patients visit different healthcare facilities, under-recording of death data, restricted populations (e.g., only working population), and unspecific date information (i.e., month rather than day).

Conclusions:

A number of heterogenous databases in Japan contain RWD suitable for assessing medication safety and effectiveness. While these databases are frequently used to generate RWE, researchers should be aware of the limitations and specificities associated with each data source. Selecting appropriate statistical methods and understanding how to interpret the results correctly given the database limitations remain the main challenges when leveraging Japanese RWD.