In Japan's public policy, nudges have been attracting attention as a new policy method to help people voluntarily make better choices for themselves. Characterized by preserving freedom of choice and being highly cost-effective, nudges are used by over 400 organizations (so-called “nudge units”) around the world in a variety of policy areas, including health and medicine, the environment and energy, taxation, and work style reform. Japan's Nudge Unit, the Behavioral Sciences Team, which promotes the use of knowledge from behavioral sciences including nudges, is an all-Japan organization comprising industry, academia, government, and the private sector, that is working together to discuss a variety of fields, to solve social issues caused by behavior. In the health and medicine fields, we have discussed the use and points to note regarding nudges, using examples such as efforts to achieve synergistic effects between health and the environment, efforts to promote vegetable intake to extend healthy lifespan, efforts to increase cancer screening rates, efforts to train and move the body, and efforts to promote behavioral changes to combat COVID-19. The use of nudges, like other policy measures, can intervene in people's lives and affect their behavior. In recent years, ethical issues, such as inappropriate activities known as “sludge” have been observed. Those involved in the use of nudges are required to adhere to high ethical standards in addition to the requirements of the law. Regardless of whether they are public or private, it is necessary to promote the use of nudges while keeping ethical considerations in mind, taking into account their acceptability to the recipients of the nudge.

In the fourth phase of the Specific Health Checkups and Specific Health Guidance, which commenced in 2024, outcome evaluation, including behavioral change in addition to a reduction in abdominal circumference and body weight, has been newly introduced. The Specific Health Guidance is designed to prevent the future onset of lifestyle-related diseases, with the additional objective of reducing medical expenses. In the discussions on the revision of the fourth-stage specific health checkups and specific health guidance, the introduction of outcome evaluation was generally viewed favorably. However, it was also suggested that the responsibility of insurers to deliver results from specific health guidance might impact the system. With this revision, outcome evaluation will be conducted in stages, in conjunction with behavioral changes. However, concerns have been raised regarding the feasibility of having insurers objectively assess behavioral change as a duty, and the discrepancy between the objective of specific health guidance and the aforementioned assessment. Nevertheless, the opinion that evaluating behavioral change in addition to abdominal circumference and weight loss will result in self-care amongst the target population was largely endorsed. There were mixed opinions regarding the evaluation of behavioral change as an outcome of the specified health guidance. It is necessary to conduct further deliberation during the fourth planning period, through data accumulation. Moreover, in the context of specific health guidance, it is crucial to facilitate the “visualization” of information pertaining to the behavioral changes of the target group. This necessitates the establishment of a system that enables insurers to assess the status of achievement of outcomes and to examine the factors contributing to success. This will ensure the provision of high-quality health guidance to the target group. It is hoped that this revision will provide an opportunity for insurers to contribute to the development of specific health screening.

Objectives: Various screening recommendations using nudge theory have recently become a focus of attention. We have reported an approach to creating an invitation postcard for screening for periodontal disease using nudge theory in Sasebo City, Nagasaki Prefecture, and observed the annual change in the participation rate of screening for periodontal disease. Methods: An invitation postcard for screening for periodontal disease using nudge theory was designed by Sasebo City and sent to a total of 3,642 residents aged 40, 50, and 60 years at the end of October 2021. A questionnaire survey on the focus points in the postcard was conducted on 131 persons who brought the postcard with them to receive screening for periodontal disease at the dental clinics. In addition, the annual participation rate of screening for periodontal disease was calculated using the Sasebo City Health Statistics, and a Joinpoint analysis was performed to evaluate the annual trends. Results: The results of the questionnaire survey showed that 45.9% of the participants had not visited the dental clinic for more than one year. The percentage of respondents who chose "free screening" as the reason for receiving screening and "neighborhood" as the reason for choosing a dental clinic was significantly higher among those aged 40 years. The part of the postcard that received the most focus was the part that clearly stated that the screening was free. When the redesigned postcards were sent, the participation rate in periodontal screening increased significantly compared with the 2021 fiscal year. Conclusion: The inclusion of "free" on the invitation postcards for screening for periodontal disease was the most attractive aspect to the target population. The participation rate of screening for periodontal disease increased after the redesigned postcards were sent.

Many of the social issues that are currently being addressed require human involvement, making them difficult to solve with just a solution. For example, even if there is technology to monitor health status and a method to improve it, the actual subject may not take actions to monitor their own status, and even if they do monitor it, they may not take measures to improve it. Even in environmental issues and everyday life (urban development) issues that need to be solved to realize a sustainable society, no matter how advanced developments in recycling technologies and mechanisms become, it is important for residents to continue collecting waste in their daily lives in order to utilize them. In urban development efforts, the efforts of governments and companies alone are not enough, and it is essential for residents living in the area to be actively and continuously involved. In other words, people's proactive change of behavior, or “behavioral change,” is extremely important for problem solving. For these reasons, in recent years, behavioral economics methods and approaches called “nudges,” along with behavioral observation and marketing methods to understand consumers, have attracted attention as strategies and methods for promoting behavior change. For this reason, big data analysis and utilization of consumer purchasing behavior history data and internet browsing behavior history data are expected. While these have a long history in their own fields, with the recent spread of digital technology, the recording and accumulation of data, and the utilization of accumulated data through data science and artificial intelligence technology have become commonplace, and they can now be regarded as a common framework. In this paper, we introduce a probabilistic approach, Bayesian network, and probabilistic latent semantic analysis that handles “behavior change” within a framework in which human behavior is recorded and accumulated as data and which utilizes that data, as well as examples of applications of these methods to behavior change support technologies.

Objectives: Social norms are crucial for understanding and explaining human social behavior. Studying such behavioral factors will contribute to the social implementation of nudges. Researchers have investigated COVID-19 preventive behaviors. This paper explains the Focus Theory of Normative Conduct and its mathematical model and analyses voluntary restraint against going out during the COVID-19 and post-pandemic periods. The Focus Theory of Normative Conduct posits that behavior is determined by whether an individual focuses on the aspect of the behavior that satisfies descriptive norms, i.e., norms based on the perception of what most people are doing, or injunctive norms, i.e., norms based on the perception of what others in the group believe an individual should do. Methods: We conducted web surveys in 2021 and 2023, focusing on COVID-19-related decision-making scenarios. We estimated parameters related to the decision-maker's attention using a mathematical model of the focus theory of normative conduct and compared these parameters across the survey years. This comparison enabled us to use a mathematical decision-making model to examine how people's attention to injunctive and descriptive norms changed during the COVID-19 and post-pandemic periods. Results: Including information about “variants” in messages advising against non-essential outings increased the likelihood of people avoiding going out and heightened their attention to injunctive norms. Furthermore, the comparative analysis between the survey years indicated a trend where attention to injunctive norms became more pronounced post-pandemic than during the pandemic. Conclusion: The increased attention to injunctive norms suggests that individuals chose to refrain from going out more due to the belief that they should avoid non-essential outings (injunctive norm) rather than because others were doing so (descriptive norm). This study indicates that incorporating information about “variants” in messages would emphasize the belief that non-essential outings should be avoided. Additionally, this tendency was stronger post-pandemic than during the pandemic.

Housing selection behavior is complex. The WHO housing and health guidelines in 2018 make recommendations for eliminating overcrowding, avoiding excessive cold and ensuring a temperature of 18°C or higher, preventing excessive heat, preventing accidents in the home, and providing barrier-free access. This paper reviews the situation surrounding housing selection behavior in Japan, with reference to statistical data, legal systems, and previous studies. The paper then reviews the state of intervention in housing policy in Japan and the UK, based on “the intervention ladder” concerning healthy and comfortable housing selection behavior. In Japan, although the development of the Performance Indication System, the Building Energy Conservation Law, and the CASBEE health checklist has already been actively promoted, the level of intervention in Japan is not high compared to that in the UK, which has a system for determining the occupant performance of housing and issuing renovation orders, as necessary. The level of intervention in Japan is not high. Although policies to enhance residential literacy and to guide people through incentives have been implemented, some mechanisms are required to assist appropriate housing selection behavior from the viewpoint of health and quality of life. housing and health, comfort, selection behavior, the intervention ladder

Objectives: The objective of the third term of Health Japan 21 is to “extend healthy life expectancy and reduce health inequalities.” Health maintenance and promotion measures must be implemented continuously and systematically from a medium- to long-term perspective. Therefore, it is important to promote measures in accordance with the Plan-Do-Check-Act (PDCA) cycle. To foster effective and efficient community health promotion and the PDCA cycle of health activities, project evaluations were introduced into activities of the National Health Insurance Insurer Effort Support System. However, what types of activities are related to a healthy life expectancy remain unclear. Therefore, this study clarified the relationship between each project evaluation score and changes in healthy life expectancy. Methods: This study used a regional correlation method with a longitudinal design and analyzed 1,147 municipalities, excluding those with a population of less than 12,000 (in 2021) and where the error in the calculation of healthy life expectancy was large. The percentage was calculated using the annual project evaluation scores submitted by the municipalities to the Ministry of Health, Labour and Welfare, based on the project evaluation of the system for 2017–2021. Healthy life expectancy of municipal populations was represented by the average healthy period at 65 years and was calculated for each gender using the “period during which people are independent in daily living activities”; a nursing care requirement of 2 or above denoted an unhealthy period. This calculation was based on the “the period during which people can live without being restricted in their daily lives by health problems” in Health Japan 21. Multiple regression analysis was conducted using each project evaluation score as an explanatory variable and the logarithm of healthy life expectancy, taxable income, and density of inhabitable land as adjustment variables for 2017. Results: For both men and women, the rates of specified health checkups, specified health guidance, and reduction in the number of persons with metabolic syndrome and pre-metabolic syndrome (men: β=0.153, p<0.001; women: β=0.087, p=0.003), promotion of community comprehensive care (men: β=0.059, p=0.043; women: β=0.065, p=0.020), and third-party reimbursement (male: β=0.059, p=0.041, female: β=0.067, p=0.017). Further, the higher the project evaluation score, the longer the healthy life expectancy. Conclusion: The project evaluation scores for the rates of specified health checkups, specified health guidance, reduction in the number of persons with metabolic syndrome and pre-metabolic syndrome, promotion of community-based comprehensive care, and third-party reimbursement were associated with the promotion of healthy life expectancy. These projects are easily adapted to PDCA and may contribute to the extension of healthy life expectancy."

Since the ‘Patient Safety Promotion Comprehensive Measures’ report in 2002, Japan's medical safety system has been established utilizing financial incentives based on medical fee additions. In addition to audits based on the Medical Care Act, the system incorporates third-party evaluations and certifications related to hospital functions. Furthermore, since 2006, the implementation of the Preferential Patient Safety Countermeasure (PPSCF) Fee 1 and 2, and since 2018, Additional Fee for the Local Network (AFLN) 1 and 2, which include peer-to-peer assessments, have contributed to building a patient safety system of international caliber. However, comprehensive reports on the overview of this system and the current situation in Japan have been scarce. This study aims to provide an overview of Japan's patient safety measures, with a specific focus on local network sheets, peer reviews, and third-party evaluations, highlighting the features of these initiatives in Japan.

Vaccinations are one of the most cost-effective medical investments that is included in the Sustainable Development Goals (SDGs). Zero-dose children are especially those who have not yet received their first DTP (diphtheria, tetanus, pertussis) vaccine, out of three in total. International organizations and public-private partnerships use DTP-1 as an indicator for vaccine programs. Until 2019, vaccine rates were steadily increasing, scoring 90% at 2019. However, there has been seen significant decline in two years, marking 86% in 2021. This was brought by closures and overworking of healthcare facilities, quarantine and supply insufficiency due to COVID-19, vaccine distrust, conflict and impacts of climate change. Japan made a remarkable devotion to COVID-19 Vaccines Global Access (COVAX) that aimed to equal distribution of COVID-19 vaccination, and to “Last One Mile Support” to transport vaccines to hospitals and health centers. COVAX has ended its mission in 2023, and the next global vaccine movement is Phase 6 of Gavi funding starting in 2026. It is highly significant for Japan to express its positive commitment and cooperate with the remaining Zero-dose problems worldwide.