SEMINAR
Linkage of medical administrative claims and long-term care claims in DeSC database
2026 年 8 巻 3 号 p. 101-104
詳細
2026 年 8 巻 3 号 p. 101-104
The DeSC database, launched in 2020 by DeSC Healthcare Co., Ltd. is a commercially available Japanese administrative medical claims and health checkup database. Recently, long-term care insurance (LTCI) claims data—covering care-need levels, monthly care benefits, service utilization, and cost information—have been integrated into the database. We showed that the distributions of the seven care-need levels were highly similar between the DeSC database and the official report by the Ministry of Health, Labour and Welfare. This similarity supports the representativeness and reliability of the DeSC database for epidemiological analyses using care-need status, particularly in the Advanced Elderly Medical Service System. This integrated dataset bridges critical information gaps and offers substantial advantages for health services research and epidemiological studies through individual-level linkage of medical, pharmacy, and LTCI claims. This study provides an overview of the LTCI claims data and available data items in the DeSC database and discusses future research prospects, with a particular focus on the linkage between medical and LTCI claims.
The DeSC database, established by DeSC Healthcare Co., Ltd. in 2020, is a commercially available administrative database that includes medical claims and health checkup data from Japan1),2). The database contains claims data from all three major insurer types: Health Insurance Societies (Kempo), National Health Insurance (Kokuho), and the Advanced Elderly Medical Service System. This comprehensive coverage enables the DeSC database to represent a broad age range—from children to older adults—and provides a more representative sample of the Japanese population than databases limited to a single insurer type.
Recently, the DeSC database incorporated long-term care insurance (LTCI) claims data, enabling individual-level linkage of medical, pharmacy, and LTCI claims. The integration of medical and LTCI claims data offers substantial research advantages by supporting comprehensive and longitudinal analyses across both healthcare and long-term care domains. This facilitates evaluations such as examining associations between medical interventions and subsequent changes in care-need levels. Furthermore, it can help identify prognostic factors that influence care-need levels among individuals covered by LTCI3).
Japan’s public LTCI system was launched in 20004). Primary insureds are residents aged 65 years or older, and secondary insureds are residents aged 40–64 years who require care due to 1 of 16 predetermined diseases (including end-stage cancer, Alzheimer’s disease, and stroke). When individuals require long-term nursing care or support for daily activities, they submit an application for care-need certification to the local municipal office. After the application, the following steps are performed to obtain certification: (1) Trained local government officials assess the need for nursing care using a questionnaire comprising 74 multiple-choice questions. The questionnaire covers six domains—physical function and mobility, activities of daily living, cognitive function, mental and behavioral disorders, social adaptation, and special medical care. (2) The attending physician or outpatient primary care physician completes a standardized document on the candidate’s condition. Based on the questionnaire and the physician’s document, candidates are assigned to 1 of 7 care-need levels: support levels 1 (requiring minimal assistance) and 2, as well as care levels 1–5 (with level 5 requiring the most assistance). Next, the Nursing Care Needs Certification Board—comprising physicians, nurses, and other health and social service experts—in each municipality determines the final care-need levels. This certification is valid for 6 months to 2 years and is typically re-evaluated once or twice annually.
Since care-need levels are determined based on an individual’s physical and mental status, they can serve as markers of activities of daily living function or disability in LTCI. Higher care-need levels are strongly associated with lower Barthel Index scores—a widely used scale that measures a person’s ability to independently perform basic activities of daily living5). Among several key health expectancy indicators, disability-free life expectancy in Japan is commonly defined as the period without disability, typically indicated by a care level of 2 or higher6–8).
Monthly LTCI claims data are collected anonymously. The database includes the following information: (1) unique individual identifiers, which allow linkage of medical claims data with LTCI data; (2) monthly care-need levels information, 1 of 7 care-need levels; and (3) service usage and cost information, including in-home and facility-based services. Each monthly claims dataset also includes the period during which an individual’s care-need certification remains valid. In the Japanese LTCI system, a service code consists of 6 alphanumeric characters divided into 2 parts: the first 2 characters represent the service category code, and the last 4 characters represent the detailed service item code. Service category codes (i.e. the first 2 digits) are available from the DeSC database. These codes enable identification of services used by LTCI beneficiaries, such as visiting, commuting, short-stay, and nursing home care services.
Since most LTCI data were introduced into the database in 2023, we describe the distribution of the 7 distinct care-need levels among individuals officially certified as requiring long-term care in April 2023, stratified by age group. We identified individuals aged ≥75 years who were officially certified as requiring long-term care and enrolled in the Advanced Elderly Medical Service System database in April 2023. Overall, 450,480 individuals were officially certified as requiring long-term care as of April 2023. We described the distribution of care-need levels across age groups (75–79, 80–84, 85–89, and ≥90 years) using data from both the database and an official report by the Ministry of Health, Labour and Welfare (Fig. 1)9). The distributions of the seven care-need levels were highly similar between the DeSC database and the official report. The distribution of care-need levels tended to shift toward higher levels with increasing age in both sources. This similarity supports the representativeness and reliability of the DeSC database for epidemiological analyses of care-need status, particularly in the Advanced Elderly Medical Service System. This study was approved by the Institutional Review Board of The University of Tokyo [approval number: 2021010NI (April 23rd, 2021)] and followed the guidelines established in the Declaration of Helsinki. As all data were de-identified, the requirement for patients’ informed consent was waived.
The bar chart shows the number of individuals at each care-need level (SLs 1 and 2, as well as CLs 1–5) by age group (75–79, 80–84, 85–89, and ≥90 years). SL 1 requires minimal assistance, while CL 5 requires the most assistance.
CL, care level; MHLW, the Ministry of Health, Labour and Welfare; SL, support level
Japanese LTCI databases are increasingly used in health services research and epidemiological studies. Data on care-need certification, service types, and the amount of care provided under the LTCI are valuable for research3). Linking LTCI claims to other data, particularly medical claims, helps address knowledge gaps, such as the association of medical procedures with worsening care-need level and health outcomes by care-need classification.
Such linkages have been considered only within a few limited municipalities, which poses significant challenges, particularly regarding data access. In contrast, the commercially available DeSC database offers broader accessibility.
Previous studies using linked medical and LTCI claims in municipalities employed care-need levels to define outcomes such as worsened care-need status (indicated by a change in care-need levels or the incidence of becoming bedridden, defined as care levels 4–5)10–14). They also used care-need levels to define baseline characteristics of the target populations15),16). For example, some studies investigated the incidence of worsened care-need levels (based on LTCI claims) following medical procedures (based on medical claims). To conduct such research, commercially available databases are recommended as alternatives to municipality-level linked medical and LTCI claims data.
The integration of LTCI claims data into the DeSC database is expected to advance health services research in Japan. By enabling individual-level linkage across medical, pharmacy, and LTCI claims data, researchers will have greater opportunities to conduct diverse studies, particularly in clinical epidemiology.
YM and YS are affiliated with the Department of Real-world Evidence, which is a cooperative program between the University of Tokyo and DeSC Healthcare. AO is affiliated with the Department of Prevention of Diabetes and Lifestyle-Related Diseases, which is a cooperative program between the University of Tokyo and Asahi Mutual Life Insurance Company.
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YM: Conceptualization, Analysis, Writing the original draft, AO and YS: Review and Editing of the draft.
All authors have read and approved the final version of the manuscript for publication and agree to be accountable for all aspects of the work, ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Akira Okada and Yusuke Sasabuchi are the Editorial Board members of Annals of Clinical Epidemiology (ACE). They were not involved in the peer-review or decision-making process for this paper.
