In the present study, we analyzed the effects of prevention services to prevent or impede the deterioration in the level of certified care need of LTCI in Japan. The prevention services were effective only in those aged over 85 and needing mild care. In the other groups, use of the prevention service did not maintain the level of certified care needed. Previous studies examined the effects on only specific aged groups,15 and did not conduct analysis with varying aged groups. Our results showed the effects of preventive services in comparison with varied age and status of disability.
Our findings indicate that prevention services may not be effective for everyone. Prevention service of LTCI in Japan was initially started as a "preventive care benefit" based on uniform national standards and rewards. From April 2015 onward, the two preventive services (visiting and outpatient care) were transferred to the “Community support program” operated by local governments. For these two services, the financial structure is the same as that for preventive benefit. However, each local government can decide its own standards and rewards. Services can be operated in various forms such as services with more flexible standards and services by residents, including volunteers. For local governments, it is necessary to consider more effective resource allocation in the future when available resources become limited. Our results can allow governments to consider which groups or characteristic segments should be targeted for effective intervention. We demonstrated the potential effects of preventive services for some groups of people. The local government as an insurer of LTCI must identify the groups that may benefit from preventive services in their areas.
Older age was a factor of deterioration in previous studies.15 25 Especially in some studies with multivariable analysis, older age was a significant factor of deterioration in the adjusted model,15 which is consistent with our results in the primary analysis (Table 2). No previous study has analyzed the effects to avoid their deterioration in the older-aged group. In our results, preventive services were effective only in older age and for mildly disabled individuals. This significant effect of prevention services seemed to depend on the potential characteristics among those who needed care services for the first time. The subjects aged 85 and over without certification were expected to spend their lives with small disabilities or problems in health. In that group (age > = 85 and support level 1), there are many persons who are potentially better than those in other groups26 Therefore, it seems that this group was likely to have an effect of preventive care.
The strengths of our study are based on using public claim data. Using public administrative data allowed us to follow the entire population of one city, unlike some previous studies that adopted a pre-post intervention of the specific groups as their study design.8 9 13 In this study, we collected information on the use of medical services and co-morbidities for adjustment using NHI claim data. Further, we extracted the status of cognitive impairment from the certification survey data, which included the factors of deterioration in the previous analysis.24 This variable collection across data became possible only by linking several administrative data between individuals. Our study was the first one to use linked administrative data for evaluating preventive services.
There were four limitations to be considered in the present study. Firstly, we defined the preventive services provided only during the six months after participants’ initial certification of LTCI. The effect of preventive service provided at any time was not examined correctly. Therefore, there was some limitation in the time of service provision. We focused on the first duration after first certification because we expected that during this period, their needs would be new, thus motivating them for service use. Even for local government experts, such a duration of service use enables accurately considering subjects’ needs.
Second, this study focuses on only one location. Therefore, the effects of the characteristics and resource allocation of the participants based on the location must be considered. However, this study is the first to evaluate preventive services based on the certified level of LTCI using insurance claim data. Our study reveals useful methods and findings for future local government-based interventions.
Third, the first certification of LTCI was defined based on the local government records during the observed period. The individual identification depended on the insured person number that was applied by the local government. The insured person number was changed when the person moved from one location to another. Therefore, it was impossible to identify whether the person had LTCI certification before moving. This limitation also affects the use of the claim data, even if it was nationwide. Such restrictions on individual tracking are difficult unless individual numbers are assigned to each citizen, and the countermeasures will be an issue for future studies.
Fourth, those who used prevention services at least once were included in the exposure group regardless of the frequency, types, or combinations of services, making it difficult to determine whether and how these components contributed to the observed effects. Future research should be conducted to examine the effects of such service usage in details.
Finally, the effects of unknown confounding cannot be denied. We tried to gather covariates using official data from the local government; nonetheless, there remains the possibility of handling other covariates by linking more existing data. This necessitates future research involving analysis of more covariates for precise results.