# Trends in heart failure prevalence in post-disaster Fukushima residents 2015–2021

## TL;DR

This study examines how heart failure rates changed among Fukushima residents aged 40 and older from 2015 to 2021, finding higher prevalence in areas affected by the 2011 disaster.

## Contribution

The study provides new insights into heart failure trends in post-disaster regions, highlighting geographic and demographic variations.

## Key findings

- Heart failure prevalence was significantly higher in coastal and evacuation zones compared to the overall Fukushima region.
- In men, heart failure prevalence increased continuously with the highest annual percentage change in the evacuation zone.
- Cohort rate ratios showed significant increases for men born between 1925 and 1975 but mixed trends for women.

## Abstract

This study aimed to investigate the prevalence of heart failure (HF) among adults aged ≥ 40 years using health checkup and medical claim data in Fukushima from 2015 to 2021. Joinpoint regression and age-period-cohort analyses were conducted to estimate temporal trends. Age-standardized prevalence and hospital admission rates for HF were 37.0 and 7.4/1000 and 25.9 and 5.3/1000 for men and women, respectively. The prevalence was significantly higher in the coastal area and evacuation zone designated after the 2011 disaster compared to the prefecture overall. In men, the prevalence increased continuously, with an average annual percentage change (AAPC) ranging from 0.72% (evacuation zone) to 1.15% (mountainous area) (P < 0.05). In total residents, the AAPC was significant only in the mountainous areas (0.78%, P = 0.021). Age-period-cohort analysis showed a net drift of 2.50% (95% CI 1.88–3.13%) in men and 0.76% (95% CI − 0.17–1.70%) in women. Cohort rate ratios increased significantly in men born between 1925 and 1975, while in women, they decreased for those born between 1925 and 1960 but increased for those born between 1960 and 1970. The prevalence of HF varied across post-disaster areas of Fukushima. Given that pathological changes and modifiable risk factors for HF accumulate gradually, continuous monitoring among middle-aged adults is essential to enable timely prevention and targeted intervention.

The online version contains supplementary material available at 10.1038/s41598-026-36032-0.