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Abstract: FR-OR90

Regional Variation in the Use of Percutaneous Kidney Biopsy in Japan

Session Information

Category: Diversity and Equity in Kidney Health

  • 900 Diversity and Equity in Kidney Health

Authors

  • Oda, Yasuhiro, The University of Tokyo Graduate School of Medicine, Bunkyo, Tokyo, Japan
  • Nishi, Hiroshi, The University of Tokyo Graduate School of Medicine, Bunkyo, Tokyo, Japan
  • Nangaku, Masaomi, The University of Tokyo Graduate School of Medicine, Bunkyo, Tokyo, Japan
Background

Several studies have conducted questionnaires on kidney biopsies performed in Japan, but there is no exhaustive survey of all kidney biopsies in Japan. Moreover, it is unknown whether there is a regional variation in the use of percutaneous kidney biopsies in Japan.

Methods

The number of percutaneous kidney biopsies stratified by the demographic data of the patients was obtained from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. Data from other nationwide surveys, including the population census, kidney transplant registry, dialysis registry and statistics of physicians, were also used. Pearson’s product-moment correlation coefficient was calculated using the R system for statistical computing.

Results

A total of 22,419 health insurance claims for percutaneous kidney biopsy in the fiscal year 2020 was registered in the database. The majority (99.9%) was inpatient percutaneous kidney biopsy. There was a large difference in the number of inpatient percutaneous kidney biopsies per population among prefectures, which could be up to 4.8 times as large in one prefecture than in another, even after adjusting for age. The number of inpatient percutaneous kidney biopsies per population positively correlated with the number of annual kidney transplants per population (R = 0.39, p = 0.006) and the number of patients on peritoneal dialysis per population (R = 0.47, p < 0.001). There was a weak negative correlation between the number of inpatient percutaneous kidney biopsies per population and the prevalence of reduced kidney function in the population aged 40–74 years (R = −0.36, p = 0.013). The frequency of kidney biopsy had no correlation with the number of patients on hemodialysis or the number of nephrologists or urologists per population.

Conclusion

The National Database of Health Insurance Claims and Specific Health Checkups of Japan revealed for the first time that more than 20,000 kidney biopsies were performed per year in Japan, as of 2020. Peritoneal dialysis and kidney transplant are offered more frequently in prefectures with a higher frequency of kidney biopsy. Further research is warranted to understand the reason for the wide regional variation in the frequency of kidney biopsy.