Using six years of integrated claims and long-term care certification data from about 400,000 older adults in Kobe, the study found that severe care dependency rises nonlinearly with age and shifts from male predominance at ages 65-74 to female predominance at ages ≥80, indicating that long-term care needs are increasingly concentrated among the oldest-old women.
The overall older population in Kobe City remained stable from FY2017 to FY2022, but the proportion aged ≥85 years, particularly women, increased.
The most prevalent disease categories were digestive, endocrine/metabolic, musculoskeletal, circulatory, neurological, and ophthalmological disorders.
Many disease categories showed a transient decline during the COVID-19 pandemic, whereas circulatory and endocrine/metabolic diseases continued to increase.
Both the number and prevalence of long-term care certifications increased throughout the study period and were consistently higher among women.
Severe care dependency (Care Need Level ≥2) increased markedly among individuals aged ≥85 years, especially women.
Logistic regression showed a nonlinear increase in the odds of severe care dependency with advancing age, with women aged ≥85 having an odds ratio of about 46 relative to women aged 65-69.
Significant age-by-sex interactions were found, with severe care dependency shifting from male predominance at ages 65-74 to female predominance at ages ≥80.
Long-term care needs are increasingly concentrated among the oldest-old women.
This study looked at six years of health insurance and long-term care records for about 400,000 people aged 65 and over in Kobe, Japan. It examined how the age makeup of the population, common diseases, and the need for long-term care changed between 2017 and 2022. The total number of older adults stayed about the same, but the share aged 85 and older grew, especially among women. Long-term care certification rose over the period and was consistently higher among women. The study found that the chance of needing a high level of care (Care Need Level 2 or above) climbs steeply and non-linearly with age. Women aged 85 and over had roughly 46 times the odds of severe care dependency compared with women aged 65-69. The sex pattern also reversed with age: among people in their late 60s and early 70s, men were more likely to have severe dependency, while from age 80 onward, women were more likely. Some diseases, such as circulatory and endocrine/metabolic conditions, kept rising even during the COVID-19 pandemic, when many other diagnoses temporarily dipped. This research suggests that planning for long-term care may need to focus on the oldest-old, particularly women, who make up a growing share of those needing intensive support. Because the study is a repeated cross-sectional analysis from one city, it shows associations and trends rather than causes, and results may not apply everywhere.
Kawai M, Kurebayashi Y. (2026). Age-Dependent Reversal of Sex Differences in Severe Long-Term Care Dependency: A Six-Year Analysis of Integrated Healthcare and Long-Term Care Data.. The Kobe journal of medical sciences. https://doi.org/10.24546/0100505678