Subtypes of Older Adults Starting Long-Term Care in Japan: Application of Latent Class Analysis

Yoko Hamasaki; Masao Iwagami; Jun Komiyama; Yuji Ito; Yuta Taniguchi; Ryota Inokuchi; Taeko Watanabe; Tadahiro Goto; Naoaki Kuroda; Ai Suzuki; Satoru Yoshie; Keitaro Kume; Tatsuro Ishizaki; Katsuya Iijima; Nanako Tamiya

doi:10.1016/j.jamda.2025.105589

Subtypes of Older Adults Starting Long-Term Care in Japan: Application of Latent Class Analysis

J Am Med Dir Assoc. 2025 Jun;26(6):105589. doi: 10.1016/j.jamda.2025.105589. Epub 2025 May 3.

Authors

Yoko Hamasaki¹, Masao Iwagami², Jun Komiyama³, Yuji Ito⁴, Yuta Taniguchi³, Ryota Inokuchi⁵, Taeko Watanabe⁶, Tadahiro Goto⁷, Naoaki Kuroda⁸, Ai Suzuki⁹, Satoru Yoshie¹⁰, Keitaro Kume¹¹, Tatsuro Ishizaki¹², Katsuya Iijima¹³, Nanako Tamiya¹⁴

Affiliations

¹ Degree Programs in Comprehensive Human Sciences, Graduate School of Comprehensive Human Sciences, Doctoral Program in Public Health, University of Tsukuba, Ibaraki, Japan; Health Services Research and Development Center, University of Tsukuba, Ibaraki, Japan.
² Health Services Research and Development Center, University of Tsukuba, Ibaraki, Japan; Department of Health Services Research, Institute of Medicine, University of Tsukuba, Ibaraki, Japan; Cybermedicine Research Center, University of Tsukuba, Ibaraki, Japan. Electronic address: iwagami@md.tsukuba.ac.jp.
³ Health Services Research and Development Center, University of Tsukuba, Ibaraki, Japan; Department of Health Services Research, Institute of Medicine, University of Tsukuba, Ibaraki, Japan.
⁴ Health Services Research and Development Center, University of Tsukuba, Ibaraki, Japan; Department of General Internal Medicine, Chutoen General Medical Center, Shizuoka, Japan.
⁵ Health Services Research and Development Center, University of Tsukuba, Ibaraki, Japan.
⁶ Health Services Research and Development Center, University of Tsukuba, Ibaraki, Japan; Department of Health Services Research, Institute of Medicine, University of Tsukuba, Ibaraki, Japan; Cybermedicine Research Center, University of Tsukuba, Ibaraki, Japan.
⁷ Department of Health Data Science, Graduate School of Data Science, Yokohama City University, Kanagawa, Japan; TXP Research, TXP Medical Co. Ltd., Tokyo, Japan.
⁸ Health Services Research and Development Center, University of Tsukuba, Ibaraki, Japan; Health Department, Tsukuba City, Ibaraki, Japan; Department of Public Mental Health Research, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan.
⁹ Degree Programs in Comprehensive Human Sciences, Graduate School of Comprehensive Human Sciences, Doctoral Program in Public Health, University of Tsukuba, Ibaraki, Japan; Health Department, Tsukuba City, Ibaraki, Japan.
¹⁰ Health Services Research and Development Center, University of Tsukuba, Ibaraki, Japan; Institute of Gerontology, The University of Tokyo, Tokyo, Japan; Institute for Future Initiatives, The University of Tokyo, Tokyo, Japan; Department of Health Policy and Management, School of Medicine, Keio University, Tokyo, Japan; School of Medicine, Hiroshima University, Hiroshima, Japan.
¹¹ Cybermedicine Research Center, University of Tsukuba, Ibaraki, Japan; Laboratory of Mathematical Informatics in Medicine, Institute of Medicine, University of Tsukuba, Ibaraki, Japan.
¹² Human Care Research Team, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan.
¹³ Institute of Gerontology, The University of Tokyo, Tokyo, Japan; Institute for Future Initiatives, The University of Tokyo, Tokyo, Japan.
¹⁴ Health Services Research and Development Center, University of Tsukuba, Ibaraki, Japan; Department of Health Services Research, Institute of Medicine, University of Tsukuba, Ibaraki, Japan; Cybermedicine Research Center, University of Tsukuba, Ibaraki, Japan; Center for Artificial Intelligence Research, University of Tsukuba, Tsukuba, Ibaraki, Japan.

PMID: 40233810
DOI: 10.1016/j.jamda.2025.105589

Abstract

Objectives: Older adults requiring long-term care (LTC) exhibit heterogeneity in physical and cognitive functions; however, an established classification is lacking. We aimed to identify distinct subgroups of older adults with LTC needs and to examine differences in their prognoses.

Design: Retrospective cohort study.

Setting and participants: Using survey data for care-need certification (linked to LTC and medical claims) in City A, Japan, we identified community-dwelling adults aged ≥65 years who started LTC. Data from City B were used to examine the validity of clustering.

Methods: We applied latent class analysis to group the participants in City A based on all 74 items [20 on body function/bed mobility, 12 on activities of daily living (ADLs), 6 on instrumental ADLs, 9 on cognitive functions, 15 on behavioral problems, and 12 on medical procedures] from the standardized care-needs certification survey. Then, we examined associations between identified subtypes and 4 outcomes, including death, hospitalization, admission to LTC facilities, and care-need level deterioration, using regression models.

Results: Among 3841 participants in City A (median age: 83 years; 59.3% female), 5 subtypes were identified: (1) mild physical, (2) mild cognitive, (3) moderate physical, (4) moderate multicomponent, and (5) severe multicomponent. The results of clustering were validated in City B. Compared with the mild physical subtype, the severe multicomponent subtype showed the highest risk of death [adjusted hazard ratio (aHR), 2.56; 95% confidence interval (CI), 2.02-3.24] and admission to LTC facilities (aHR, 5.91; 95% CI, 4.57-7.63). The moderate physical subtype showed a higher risk of hospitalization (aHR, 1.32; 95% CI, 1.16-1.49), and the moderate multicomponent subtype was more likely to experience care-need deterioration (adjusted odds ratio, 1.67; 95% CI, 1.26-2.22).

Conclusions and implications: This study identified 5 subtypes of older adults requiring LTC. These findings inform individualized care decisions and tailored planning of medical and LTC services.

Keywords: Long-term care; latent class analysis; older adults; subtypes.

MeSH terms

Activities of Daily Living
Aged
Aged, 80 and over
Female
Geriatric Assessment
Humans
Independent Living
Japan
Latent Class Analysis
Long-Term Care*
Male
Retrospective Studies