Recent trends in dialysis initiation in Japan: a region‑specific descriptive analysis using Hokkaido as an example

BACKGROUND: The increasing number of dialysis patients presents a significant public health challenge in Japan. While the number of patients initiating dialysis due to chronic glomerulonephritis (CGN) or diabetic kidney disease (DKD) has decreased, the incidence of dialysis initiation attributed to nephrosclerosis has gradually increased. To investigate regional differences, Hokkaido, Japan, was selected as one regional example in this study. METHODS: Data were extracted from a web-based national database for patients aged ≥ 40 years who initiated dialysis between 2012 and 2021. Patients were categorized according to sex, age, and underlying disease. Dialysis initiation rates were calculated as the number of new dialysis patients divided by the corresponding population. To assess temporal changes, the 2021/2016 ratio was calculated by dividing the initiation rate in 2021 by that in 2016 for each prefecture. RESULTS: In Hokkaido, the dialysis initiation rates for DKD declined across all age groups, whereas the national rate increased in men aged ≥ 80 years. For nephrosclerosis, the initiation rates rose among older adults both nationally and in Hokkaido, although the increase in Hokkaido was more gradual. CGN-related rates decreased consistently across all age groups, both nationally and in Hokkaido. Prefectures with 2021/2016 ratio of ≥ 1 were more frequently observed among patients with nephrosclerosis than among those with CGN or DKD, especially among older populations. CONCLUSIONS: Dialysis initiation rates in Hokkaido decreased in most subgroups compared with national trends. Given the rising incidence of nephrosclerosis among older adults, targeted interventions at the prefectural level are urgently warranted.