Papers

A paper authored by Associate Professor Midori Matsushima of the University of Tsukuba and a research group led by Professor Naoki Kondo has been accepted for publication in BMC Public Health. The paper elucidates the association between the COVID-19 pandemic and the postponement of pregnancy in Japan, and well-being of women who opted to delay childbearing were significantly lower than the women who did not.

During the COVID-19 pandemic, approximately 20% of married women who had initially intended to conceive before the pandemic decided to postpone their pregnancy. Furthermore, the study identified a robust connection between severe psychological distress, loneliness, and suicidal ideation during the pandemic, and the choice to delay pregnancy. These findings indicate concerns about the declining well-being of women during times of crisis and the necessity for society to establish comprehensive mental health support systems.

Article: Matsushima, M., Yamada, H., Kondo, N. et al. Married women’s decision to delay childbearing, and loneliness, severe psychological distress, and suicidal ideation under crisis: online survey data analysis from 2020 to 2021. BMC Public Health 23, 1642 (2023).

DOI:  10.1186/s12889-023-16476-z

Press Release (link to University of Tsukuba HP): p20230920140000.pdf (tsukuba.ac.jp) *in Japanese

In response to the coronavirus pandemic, it has been noted that there were significant disparities in access to medical care. The situation varied greatly from country to country. Therefore, primary health care and public health researchers from eight countries gathered to examine each country’s response situation. In particular, they clarified the current state of cooperation between the medical sector (clinics and hospitals) and the public health sector (public health centers and municipal health centers, etc.), which are emphasized in order to mitigate disparities.

As a result, it was confirmed that it is essential to develop a mechanism for cooperation between the two sectors in normal times, and in doing so, it is important to establish a mechanism that should take into account the social determinants of health (e.g., poverty, isolation, etc.) of the target population.

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Health is the cornerstone of life. Protecting the health of individuals receiving welfare support, including public assistance recipients, is especially important. Since 2021, welfare offices in Japan have been obliged to implement health management support programs for public assistance recipients. To provide health and life support efficiently and effectively, we have developed a new tailor-made support method using a marketing technique.

In marketing, the target audience for services is classified according to their characteristics (segmentation) to identify priority individuals and design services tailored to these characteristics. In applying this approach, we used data on public assistance recipients aged ≥65 years to extract five distinct segments via soft clustering, a machine learning technique. We examined the similarities between the extracted segments and public assistance recipients in practice by interviewing caseworkers at welfare offices. The results showed that caseworkers perceived several segments as those in practice. Moreover, we extracted segments with characteristics that caseworkers had not been aware of previously.

Accordingly, we have been developing a tailor-made health support system that presents support plans for each segment.

Article: Ueno, K., Nishioka, D., Saito, J. et al. Identifying meaningful subpopulation segments among older public assistance recipients: a mixed methods study to develop tailor-made health and welfare interventions. Int J Equity Health 22, 146 (2023).

https://doi.org/10.1186/s12939-023-01959-7

Many countries have been increasing their state pension age. Nonetheless, there is little consensus on whether retirement affects the risk of cardiovascular disease.

Using a causal inference approach, Mr. Sato and colleagues found a 2.2%-point decrease in the risk of heart disease and a 3.0%-point decrease in physical inactivity among retirees, compared with workers.
Policymakers need to consider the benefits of raising the state pension age and allowing older people to continue working versus the costs from the potential risk of expensive medical conditions such as cardiovascular disease.

This research has been published in International Journal of Epidemiology, one of top journals in the field of epidemiology.

In addtion, the results of this study were covered by various media outlets.

Article: Sato K, Noguchi H, Inoue K, Kawachi I, Kondo N. Retirement and cardiovascular disease: a longitudinal study in 35 countries. Int J Epidemiol. 2023 May 8 Int J Epidemiol. 2023 May 8: dyad058.

DOI: https://doi.org/10.1093/ije/dyad058

The research group led by Associate Professor Inoue, Professor Susan Athey of Stanford University, and Associate Professor Yusuke Tsugawa of the University of California, Los Angeles, has proposed the potential usefulness of the “high-benefit approach,” a next-generation personalized medicine strategy for hypertension treatment, by applying advanced machine learning models to the treatment of hypertension.

This research established a new concept focusing on individual treatment effects. It demonstrated its usefulness, and it is expected to become a basis for the next generation of personalized medicine applying machine learning.

Kosuke Inoue, Susan Athey, Yusuke Tsugawa (2023). Machine-learning-based high-benefit approach versus conventional high-risk approach in blood pressure management. International Journal of Epidemiology.

DOI: https://doi.org/10.1093/ije/dyad037

Please click on the following link for the press release and more information.
Press release: https://www.kyoto-u.ac.jp/ja/research-news/2023-04-05
Kyoto University School of Public Health: http://sph.med.kyoto-u.ac.jp/news/7016/

The research group led by Associate Professor Inoue and Associate Professor Yusuke Tsugawa of the University of California, Los Angeles (UCLA), using U.S. National Health and Nutrition Examination Survey data, has found that achieving 8,000 steps per day, even just one or two days a week has a positive impact on health.

Using accelerometer-measured step count information, the study examined the risk of mortality associated with walking more than 8,000 steps per day for 0, 1-2, and 3-7 days. The Findings, those who walked at least 8,000 degrees, even one or two days per week, showed a reduction in mortality risk almost equal to those who regularly walked three or more days per week.

The results of this study suggest that achieving the target number of steps, even one or two days per week, may have a sufficiently positive impact on health.

Kosuke Inoue, Yusuke Tsugawa, Elizabeth Rose Mayeda, Beate Ritz (2023). Association of Daily Step Patterns With Mortality in US Adults. JAMA Network Open, 6(3):e235174.

DOI: https://doi.org/10.1001/jamanetworkopen.2023.5174

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Press release: https://www.kyoto-u.ac.jp/ja/research-news/2023-03-30

Kyoto University School of Public Health: http://sph.med.kyoto-u.ac.jp/news/6979/

A research group including Assistant Professor Inoue, Assistant Professor Tatsuhiko Naito of Osaka University Graduate School of Medicine (at the time of the research/now a postdoctoral fellow at Mount Sinai School of Medicine), Professor Yukinori Okada (Team leader, RIKEN Center for Integrative Medical Sciences Laboratory for Systems Genetics / Professor of Department of Genome Informatics, Graduate School of Medicine, The University of Tokyo), and Lecturer Kenji Oki of Hiroshima University(Department of Molecular and Internal Medicine, Graduate School of Biomedical & Health Science), has conducted a genome-wide association study of primary aldosteronism, and the results were published in Circulation.

Tatsuhiko Naito, Kosuke Inoue, Kyuto Sonehara, Ryuta Baba, Takaya Kodama, Yu Otagaki, Akira Okada, Kiyotaka Itcho, Kazuhiro Kobuke, Shinji Kishimoto, Kenichi Yamamoto, BioBank Japan, Takayuki Morisaki, Yukihito Higashi, Nobuyuki Hinata, Koji Arihiro, Noboru Hattori, Yukinori Okada, Kenji Oki .Genetic Risk of Primary Aldosteronism and Its Contribution to Hypertension: A Cross-Ancestry Meta-Analysis of Genome-Wide Association Study.Circulation,21 February 2023

DOI:10.1161/CIRCULATIONAHA.122.062349

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A paper in joint research with Associate Professor Midori Matsushima at the University of Tsukuba has been published online in the Journal of Biosocial Science.

A research group led by Associate Professor Midori Matsushima, Humanities and Social Sciences, University of Tsukuba, and Professor Naoki Kondo examined the association between the COVID-19 pandemic and pregnancy postponement.

This study analyzed data on 768 women with the intention to become pregnant from The Japan COVID-19 and Society Internet Survey (JACSIS) conducted in 2020 and 2021, and found that approximately 20% of the women postponed pregnancy. Furthermore, the reason for this was not fear or anxiety about COVID-19 infection, but rather reduced income and anxiety towards future household finances due to the COVID-19, and the impact of this was particularly strong in 2021.

The results of this study showed that social factors affect the pregnancy decisions of those who wish to become pregnant, suggesting that it is important to promote the elimination of economic insecurity even after this pandemic is over.

Midori Matsushima, Hiroyuki Yamada, Naoki Kondo, Yuki Arakawa, Takahiro Tabuchi. Impact of the COVID-19 pandemic on pregnancy postponement – evidence from Japan. Journal of Biosocial Science,11 January 2023.

DOI: https://doi.org/10.1017/S0021932022000451

Abstract

Japan has faced a decline in fertility since the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to investigate the rate of pregnancy postponement and its contributing factors, with a particular focus on economic- and COVID-19 infection-related indicators. This study used data from 768 observations of married women aged 18 to 50 years with pregnancy intentions. The data were obtained from two rounds of a large web-based survey conducted by the Japan COVID-19 and Society Internet Survey (JACSIS) in 2020 and 2021. A generalised estimating equation (GEE) model was employed, as well as Poisson regression models for sub-sample analysis divided by year to estimate the year differential magnitude of the contributing factors’ impacts. Approximately 20% of married women with childbearing intentions postponed their childbearing. The analyses revealed that declining income and anxiety about future household finances were significantly related to delayed childbearing, while fear of COVID-19 and infection rate were not. Additionally, the adverse effects of unfavourable economic conditions were stronger in 2021. Notably, age did not influence the decision of pregnancy postponement. Older women postponed pregnancy just as much as younger women. In conclusion, this study revealed that the COVID-19 pandemic, particularly its related adverse economic conditions, contributed to Japan’s current baby bust. Considering that advanced maternal age is already common in Japan, this decreased fertility may result in the long-term negative consequence of further population decline.

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