Background
As Japan becomes a super-aged society, the question of how medical care for the elderly is provided and the direction of that care are important national issues. Elderly people are physically frail and consequently often have multi-morbidity [
1,
2], and thus, treatment patterns are often complex [
3‐
5]. As a result, cases of polypharmacy in elderly people are not uncommon in clinical practice [
6]. Treatment guidelines have been created with the aim of avoiding this kind of potentially inappropriate medical care, but those recommendations are not always properly implemented in clinical practice. The problem of when evidence from clinical research and treatment guidelines is not utilized in practice is called an evidence-practice gap [
7]. In the USA, there are reports on the state of evidence-based health care [
8] and proposals for narrowing the gap in actual clinical practice [
9‐
11].
In Japan, the computerization of health and medical information is progressing, and large databases have been established. The utilization of these databases is an important issue. Since the mid-2000s, private companies have created databases of health insurance society claims that are used for research purposes [
12,
13]. At the national level, National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) has been constructed together with enforcement of the “Act on Assurance of Medical Care for Elderly People” of 2008. Since 2011, the NDB has been used secondarily for research purposes.
These databases are the quantitative information to measure the actual state of medical environment. There are few research papers which reported the actual situation of medical care in elderly based on a large-scale of data in Japan [
14,
15], however, none of the papers which discuss about evidence-practice gap in elderly in super-aging society based on large-scale of data as NDB can be found currently.
In this study, we validate NDB in the onsite research center at Kyoto University Hospital, settled by the Ministry of Health, Labor and Welfare of Japan, to elucidate the actual state of medical care for the elderly and actual situation of evidence-practice gap. Research procedures are shown as follows.
First, we validate and estimate reliability of NDB using a database of the Kyoto University Hospital (including associated hospitals database), and private health insurance claims databases. Additionally, we compare the characteristic points of each database through validation and show the guidance for choosing the database depend on specific purpose.
Secondly, we elucidate how medical care for the elderly is provided in a super-aging society in Japan. To elucidate, the following three examples are settling: 1. potential inappropriate medication (PIM), 2. cancer treatment, 3. chronic kidney disease (CKD) treatment. PIM was chosen because improper use of medicine and medicine interaction caused by multiple drug administration cause adverse events and impair quality of life (QOL) of the elderly. We will conduct research that will contribute to safe medication for the elderly. The reason for choosing cancer treatment is that cancer is the disease of the main topic even in the world [
16] and it is the leading cause of death in Japan, too [
17]. The reason for choosing CKD treatment is one of the major complications of lifestyle-related diseases, and if it can delay progress by early intervention, and it will lead to improvement of QOL.
We will select databases which suit for elucidating the actual situation of these three examples based on selection guidelines by validation of NDB.
Third, through finding aspects, we will discuss the evidence-practice gap. Also, we will assess the examples in the view of medical economics, because Japan will enter the super-aged society ahead of the world, the elderly population will continue to increase [
18] and medical costs will be expected to increase. We will clarify the current situation of medical costs and lead to the creation of solutions.
For “PIM”, we will clarify the status of drug prescriptions that should be limited in elderly people and polypharmacy, and show findings that will serve to alert medical practitioners to this. In “Cancer treatment”, we will check the implementation status of treatment recommendation guidelines, which will contribute to normalization of proper treatment and elimination of disparities, and to develop a system for the provision of novel cancer care. For “CKD treatment,” we will clarify the implementation status of existing treatment quality indices, provide information that will contribute to efforts to prevent increasing severity by the insurer, and assess the effects on health care costs.
Then, comprehensively considering the findings through efforts related to the three examples above, we will focus on “Medical care provided to end-of-life elderly patients”, because QOL of elderly patients is that concerns not only elderly patients but also medical state in super-aging society as a whole. We will show the actual palliative care and other end-of-life care that is currently provided, and build a foundation for social discussion of the kind of medical care that is desirable for elderly people.
Finally, from the above, we will elucidate the current state of evidence-practice gap from the perspectives of both under- and over-treatment in the super-aging society of Japan, and analyze medical economically, together with presentation of ways to provide medical care in the future and directions for this care in aspect of epidemiology.
Strengths/Limitations
The NDB contains exhaustive data including information on nearly all health insurance claims. However, the state of insurance claims information, such as disease name and other factors, do not reflect actual clinical status of patients. A number of previous studies have indicated that validation is a common issue worldwide when using databases, but there are almost no reports from Japan. The significance of this study is in raising the validity of findings obtained by carrying out validation studies, and in the suggestions it provides for precautions and further potential uses of health insurance claims information and specific medical checkups information and the NDB, in which such data is accumulated. At the same time, the study is limited by the fact that the NDB itself cannot be linked to other data, accordingly, the NDB cannot be directly validated, and comparisons with other health care information, such as insurance claims information and test values, must be done within limited groups, such as several medical institutions.
Acknowledgements
This study is supported by a Ministry of Health, Labor and Welfare Grant-in-Aid for Scientific Research (Research on Policy Planning and Evaluation) (H27-policy-strategy-013).