Status of diagnostic test, diagnosis, and treatment of influenza using the national database of health insurance claims and specific health checkups of Japan

Background

We previously reported the status of diagnostic tests, diagnoses, and prescriptions for influenza in Japan using a large-scale nationwide database, in which the type of health insurance plan was limited and older people were omitted. In this study, we examined the status using a comprehensive Japanese health insurance claims database.

Methods

This cross-sectional study used the National Database of Health Insurance Claims and Specific Health Checkups of Japan from April 2009–March 2020. Among the target patients with at least one record of any tests, diagnoses, or prescriptions, the percentages of patients with a combination of tests, diagnoses, and prescriptions were calculated by the influenza season year (SY), demographics, and type of health insurance plan. The percentage of patients diagnosed to those who underwent tests and the percentage of patients who obtained prescriptions to those diagnosed (prescriptions/diagnoses) were calculated according to the medical facility characteristics.

Results

The database included 199,964,548 target patients; ≥90 % received either the test alone or test + diagnosis + prescription in SY 2014 and later. The two patterns were predominant at approximately ≥90 % by age in both sexes. Most patients visited medical facilities without beds, where the percentage of prescriptions/diagnoses was 88.1 %.

Conclusions

We showed that most patients diagnosed with influenza underwent diagnostic testing and were prescribed antiviral drugs using comprehensive Japanese health insurance claims data. This finding was consistent with our previous study.