Content Analysis of Health Information Exchange Usage in Japan: An Audit Log Study (Preprint)

Abstract

In Japan, research on the types of medical data demanded by healthcare workers in health information exchanges (HIEs) is limited. Previous studies have relied on questionnaires or interviews with medical workers, and the data collected have not been based on the utilization of regional HIEs.

This study aimed to identify the types of medical data that are frequently viewed on demand using HIEs in Japan.

We collected audit log data from two HIEs, Choukai Net and PicaPicaLink, covering the period from April 1, 2017, to March 31, 2022. Three types of analyses were conducted on the collected audit logs. First, we calculated the cumulative monthly usage days of the HIEs by each institution for the financial year (FY) 2021/22. Second, we calculated the view rate for each output field and content with each HIE, using facility type or year as the aggregation unit. Third, we calculated the cumulative number of viewed days for contents scheduled to be included in the national HIE compared to those that were not.

In 32.6% of hospitals connected to Choukai Net and 2.3% of hospitals connected to PicaPicaLink, cumulative monthly usage days exceeded 101. Additionally, in 32.4 % of visiting nursing stations connected to Choukai Net, cumulative monthly usage days were over 51. The overall view rate for progress notes was the highest among all content types, with 67.4% for Choukai Net and 32.9% for PicaPicaLink. In both HIEs, when comparing by facility type, the view rate for progress notes was highest for visiting nursing stations, reaching 91.8% for Choukai Net and 65.3% for PicaPicaLink. For DICOM image lists, the view rates were 13.8% for Choukai Net and 13% for PicaPicaLink. In facilities other than hospitals, the view rate for DICOM image lists was lower than that for radiology reports. The view rate of content that was scheduled to be included in the national HIE was 45.6% for Choukai Net and 47.7% for PicaPicaLink. Conversely, the view rate for contents not scheduled to be included in the national HIE was higher, with 80.2% for Choukai Net and 56.6% for PicaPicaLink.

In both HIEs analyzed in this study, progress notes were the most viewed content. In facilities other than hospitals, radiology reports were viewed more frequently than DICOM images. The results of these analyses suggest that the significance of regional HIEs compared to national HIEs lies more in their ability to view medical records written by doctors in natural language, such as progress notes and radiology reports, rather than in the ability to view DICOM images.