The aim of this article is to help develop a common understanding of the current status, challenges, and future perspectives of real-world data (RWD) and real-world evidence (RWE) in Japan. RWD and RWE are very widely used terms, but standardized definitions are lacking. Given broad and growing applications of RWD/RWE from the perspective of clinical development and medical affairs, the PhRMA Japan Medical Affairs Committee Working Group 1 have proposed the following definitions: "RWD are the data relating to patient health status and/or the delivery of health care routinely collected from a variety of sources" and "RWE is the evidence derived from analysis of RWD." The key challenges for RWD and RWE in Japan include restricted access and linkage of RWD, as well as a lack of universally accepted methodological approaches, which reduces the potential for patient and healthcare benefits. These challenges for RWD/RWE are by no means unique to Japan and similar challenges exist for countries in Europe and the USA. The quality of data and analysis, study design, and the transparency of reporting should be discussed more to ensure credibility and acceptance by decision-makers as the demand for RWD and RWE increases. The future developments around Japan's RWD and RWE are expected to include improved RWD access, data linkage, and increased acceptance by decision-makers, all supported by innovative technology. Improvements in RWD access and database linkage will enable both public and private sectors to assemble more comprehensive health information in Japan.

Introduction Limited data are available regarding the prevalence of thrombotic/cardiovascular disease and treatment patterns for patients with coronavirus disease 2019 (COVID-19) in Japan. In this study we describe patients hospitalized for COVID-19 in Japan. Methods This retrospective database study analyzed the Japan Medical Data Vision database (416 acute care hospitals) for patients hospitalized for COVID-19 during the identification period from 1 January 1 to 30 September 2020. Results Among 9282 eligible patients, 832 (9%) had developed thrombotic disease including myocardial infarction, ischemic stroke, deep vein thromboembolism and pulmonary embolism. Intriguingly, 171(1.8%) had two thrombotic events and 25 (0.3%) had three or four thrombotic events at the same time. The data also showed that arterial thrombotic events accounted for 77% of total thrombotic events. Anticoagulant and/or antiplatelet medication was provided to 3312 patients. Even with antithrombotic medication, 21.2% of patients suffered from thrombotic diseases. Conclusions Patients with COVID-19 could experience thrombotic complications in every blood vessel. Further optimization of medication is crucial for preventing thrombotic complications and improving prognosis.