Objective　In Japan, measures to prevent frailty among older adults have been implemented. Promotion of social participation is a key measure, but few longitudinal studies have examined the relationship between the types and number of social participation and frailty onset. In this study, we aimed to clarify the relationship between the types and number of social participation and frailty onset using longitudinal data from a large sample of older adults in municipalities in Japan.

Methods　We used the 2016 and 2019 panel survey data from the Japan Gerontological Evaluation Study (JAGES). The analysis included 59,545 individuals from 28 municipalities who responded to the JAGES survey in both 2016 (at baseline) and 2019 (at follow-up). We excluded individuals who were dependent on activities of daily living at baseline and non-responders, and those who were frail or with no information about frailty. The dependent variable was frailty onset (≥8 out of 25 points on the basic checklist) at follow-up, and the independent variables were the types and number of types of social participation at baseline. We included 11 variables as potential confounders. We used multiple imputations to complete the missing values and used modified Poisson regression to examine the association between social participation and risk of frailty onset.

Results　Of the 59,545 participants, 6,431 (10.8%) were frail onset at follow-up. After multiple imputations (minimum 64,212, maximum 64,287), the risk of frailty onset at follow-up was lower for eight types of social participation, excluding senior citizens' clubs, (nursing care [risk ratio; 0.91], paid work [0.90], volunteer groups [0.87], neighborhood associations [0.87], learning or cultural groups [0.87], activities intended to teach skills or pass experiences to others [0.85], hobby groups [0.81], and sports groups or clubs [0.80]; P<0.05), than no social participation. Additionally, individuals who participated in more types of social participation were at a lower risk of frailty than those with no social participation (P for trend <0.001).

Conclusions　The risk of frailty onset was lower among individuals who participated in eight types of social participation at baseline and among those who participated in more types of social participation than those with no social participation. The results suggest that social participation is a useful measure to prevent frailty for extending healthy life expectancy.

Objectives　In Japan, schools of public health (SPH) have engaged in professional education focusing on five core disciplines: epidemiology, biostatistics, social and behavioral science, health policy and management, and occupational and environmental health. However, empirical information is lacking regarding the current state of this education and its associated challenges in Japan. In this article, we showcase this issue, using the master of public health (MPH) course at Teikyo University Graduate School of Public Health (Teikyo SPH) as an example.

Methods　We summarized the current objectives and classes required to complete the MPH course at Teikyo SPH, using the course guideline published in 2022. Current issues and possible future directions in the course were summarized based on the opinions of Teikyo SPH faculty members.

Results　For epidemiology, lectures and exercises were designed to focus on how to formulating public health issues, collecting and evaluating data, and causal inference. Issues related to the design included ensuring that students had the necessary skills to apply epidemiology to emerging issues, and catching the course up with evolving techniques. For biostatistics, lectures and exercise classes focused on understanding data and statistics, as well as performing analyses. Issues included the understanding of theories, setting the course level, and a lack of appropriate education materials for emerging analytical methods. For social and behavioral science, lectures and exercise classes focused on understanding human behaviors and actions for problem solving. Issues included learning various behavioral theories in a limited timeframe, the gap between the lectures and various needs, and nurturing professionals who had the skills to perform in practical settings. For health policy and management, lectures, exercise classes, and practical training classes focused on identifying and solving problems in the community and around the world, and on integrating the disparate viewpoints of health economics and policy. Issues included few alumni who actually found work globally, a lack of students working in local or central administrations, and insufficient perspectives on rational/economic thinking and macro-economic transitions. For occupational and environmental health, lectures, exercise classes, and practical training classes focused on learning the occupational and environmental impacts of public health issues, and their countermeasures. Challenges included enriching the topics with regard to advanced technologies, environmental health, and socially vulnerable populations.

Conclusion　Through these reflections on MPH education at Teikyo SPH, the following recommendations are considered essential in order to prepare improvements to the program: reorganizing the curriculum to meet the needs of the day, accepting students with various backgrounds, addressing the increasing knowledge and skills that need to be acquired by the students, and enhancing the powers of professors to implement changes.

Objectives　To show the impact of COVID-19 on cancer treatment in Tochigi prefecture.

Methods　The number of cancer cases registered in Tochigi prefecture before (2019) and after (2020) COVID-19 was compared using cancer registry data from 18 member hospitals of the Tochigi Prefecture Cancer Care Collaboration Council. Data were compared by sex, age, patient's address at the time of diagnosis, month of diagnosis, cancer site, cancer stage, and treatment. Data on screenings for stomach, colorectum, lung, female breast, cervix, and prostate cancers were investigated in detail.

Results　The total number of registered cancer cases was 19,748 in 2019 and 18,912 in 2020 (a decrease of 836 cases [−4.2%]). Among the total cases, there were 11,223 and 10,511 males in 2019 and 2020, respectively (a decrease of 712 cases [−6.3%]) and 8,525 and 8,401 females in 2019 and 2020, respectively (a decrease of 124 cases [−1.5%]). The decrease was greater among males than among females. There was no decrease in the number of registered patients aged <40 years between 2019 and 2020. Based on the patients' address at the time of diagnosis, there was no decrease in the number of cases from outside of the Tochigi prefecture. Regarding the month of diagnosis, there was a notable decrease in the number of registered patients in May and August of 2020. Among the decrease of 836 cases detected by screening, 689(82.4%) were cases of stomach, lung, colorectum, female breast, cervix, and prostate cancer. The number of registered cases of malignant lymphoma, leukemia, and cancer of the oral cavity and pharynx, pancreas, bone and soft tissue, corpus uteri, and bladder did not decrease between 2019 and 2020. In terms of stage of cancer, the number of registered cases of carcinoma in situ, localized cancer, and regional lymph node metastases was lower in 2020 than in 2019, but there was no decrease in the number of registered cases of distant metastases or regional extension.

Conclusion　The number of cancer cases registered in 2020 was lower than in 2019, and the degree of change varied by age, hospital, site, whether the case was detected by screening, and stage of cancer. In particular, a marked decrease was observed in the number of cases detected by screening. Furthermore, the decrease in the number of cancer cases registered in May and August of 2020 were believed to be due to the peak in the spread of COVID-19 and the associated declaration of a state of emergency.