Research Trends and Structural Characteristics of Healthcare Research in Japan, Including the First Half of the New Coronavirus Spread Period: A Bibliometric Analysis.

This study aims to conduct a bibliometric analysis to characterize the trends and research features of health administration in Japan, in terms of themes and structural aspects, such as institutional affiliations, up to the early stages of the spread of the new coronavirus. Literature data were obtained from the United States National Institutes of Health (NIH) database, using the search formula (Healthcare[Title/Abstract] AND Japan[Title]), and the dataset was obtained on March 15, 2025. The total number of data points analyzed was 1066. Research trends, such as the characteristics of themes based on KeyWords Plus (Clarivate, Philadelphia, USA) and their changes, and the academic structure focusing on the country of origin, institutional affiliations, and publication journals, were quantitatively analyzed using the bibliometrics tools in the R package (Biblioshiney interface) for literature up to 2021, when the impact of coronavirus disease of 2019 (COVID-19) became pronounced in Japan. The KeyWords Plus analysis revealed a substantial research emphasis on healthcare human resources, and confirmed an increase in COVID-19-related research around 2020, when the impact of the novel coronavirus infection spread in Japan. Notably, the results of the bibliometric analysis highlight the aspect that healthcare human resources was one of the main focuses of the study area. However, limitations of textmining methods were observed in the export function of the CiNii database (National Institute of Informatics, Tokyo, Japan), which comprehensively collects articles written in Japanese. In order to grasp research trends in the field of healthcare in Japan, regardless of language, it is necessary to enhance multilingual support in Japanese academic information databases and develop an international academic information database (such as Web of Science, Scopus, OpenAlex, etc.) to expand the scope of collection.