Incidence Rate of Hospitalization for Heart Failure in a Japanese City　- An Updated Reference for Japan's Aging Society.

Background: The prevalence of heart failure (HF) is increasing in aging societies, such as Japan. The current incidence rate (IR) of HF hospitalization in Japan is unknown. Methods and Results: We conducted a regional population-based study assessing the IR of HF hospitalization in Nobeoka City. Data were collected over a period of 3 years from all patients with HF admitted for the first time to hospitals and clinics. 406 HF hospitalizations were registered (54% female; mean age 82 years). The IR of HF hospitalization was 129/100,000 person-years. The difference in the IR between women and men was not significant (131 vs. 127/100,000 person-years, respectively; P=0.767). The age-adjusted IR in the 2015 Japanese population was 105/100,000 person-years. According to 5-year age bands, the IR of HF hospitalization gradually increased up to 60-70 years of age, then increased rapidly in those aged ≥95 years for both sexes. The IR ratio compared with age <65 years was higher in women than men in each older age group. Conclusions: In this population-based study, the current IR of HF hospitalization in a region of Japan was higher than the IR from another study conducted in a different region in early 2000. By presenting detailed age-related data, the research findings will contribute to estimating the number of HF hospitalizations in other areas of Japan.