Koichiro Shiba

Koichiro Shiba, PhD

Assistant Professor, Epidemiology - Boston University School of Public Health


My overarching research goal is using rigorous causal inference thinking and methods to improve evidence on social determinants of health and health disparities. Rather than merely applying complex methods, my motto is to harness their full potential by identifying and applying the methods to the unique challenges in social epidemiologic studies where they truly shine.

I lead a multitude of projects spanning a broad spectrum of methodological issues, including but not limited to: analyzing time-varying treatments to derive different, policy-relevant insights, and identifying when conventional single-point exposure analysis may be misleading; the use of machine learning methods for robust effect estimation and assessing high-dimensional heterogeneous exposure effects, capturing the intersectionality; the consideration of causal estimands and selection bias in trauma studies with sample attrition; novel approaches to characterize and operationalize neighborhood characteristics; and a novel causal inference method to simulate the impacts of realistic hypothetical interventions on health disparities.

In addition to these methodological focuses, I have worked on several key substantive areas that address urgent public health concerns. First, I study the effects of stressful experiences and traumatic events (such as climate change, disasters, child adversity, pandemics, and global financial crises) on population health, with a particular focus on older adult populations. Second, I investigate the roles of social relationships, social engagement (e.g., volunteering), and related exposures such as loneliness and social isolation) in promoting the health of older adults and fostering resilience. I have also explored how internet-based social interactions can influence population health. Third, I study the impacts of positive psychological factors (for instance, purpose in life, Ikigai) on health. My research further delves into inequalities in and determinants of multidimensional well-being (i.e., human flourishing), which extends beyond traditional physical and mental health outcomes and include other key domains of human well-being such as purpose in life and social well-being. In essence, my objective for this line of research is to study health in its fullest sense, defined by the World Health Organization as “a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.”


  • Harvard School of Public Health, PhD Field of Study: Population Sciences
  • University of Tokyo, MPH Field of Study: Public Health
  • University of Tokyo, BA Field of Study: Health Science


  • Published on 2/6/2024

    Shiba K, Inoue K. Harnessing Causal Forests for Epidemiologic Research: Key Consideration. Am J Epidemiol. 2024 Feb 06. PMID: 38319713.

    Read At: PubMed
  • Published on 1/23/2024

    Yazawa A, Hikichi H, Shiba K, Okuzono SS, Kondo K, Sasaki S, Kawachi I. Association of disaster-related damage with inflammatory diet among older survivors of the Great East Japan Earthquake and Tsunami. Br J Nutr. 2024 Jan 23; 1-9. PMID: 38258409.

    Read At: PubMed
  • Published on 1/8/2024

    Okuzono SS, Slopen N, Shiba K, Yazawa A, Kondo K, Kawachi I. Do Adverse Childhood Experiences Modify the Association Between Disaster-Related Trauma and Cognitive Disability? Am J Epidemiol. 2024 Jan 08; 193(1):36-46. PMID: 37442811.

    Read At: PubMed
  • Published on 12/15/2023

    Toshiaki Komura, Richard G. Cowden, Ruijia Chen, Ryan M. Andrews, Koichiro Shiba. Estimating the heterogeneous effect of life satisfaction on cognitive functioning among older adults: Evidence of US and UK national surveys. SSM-Mental Health. 2023; 4.

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  • Published on 11/18/2023

    Tim Lomas, Pablo Diego-Rosell, Koichiro Shiba, Priscilla Standridge, Matthew T. Lee, Alden Yuanhong La. The world prefers a calm life, but not everyone gets to have one: global trends in valuing and experiencing calmness in the Gallup World Poll. The Journal of Positive Psychology. 2023; 1-4.

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  • Published on 11/16/2023

    Nakamura JS, Shiba K, Jensen SM, VanderWeele TJ, Kim ES. Who Benefits From Helping? Moderators of the Association Between Informal Helping and Mortality. Ann Behav Med. 2023 Nov 16; 57(12):1058-1068. PMID: 37540830.

    Read At: PubMed
  • Published on 9/30/2023

    Cowden RG, Chen ZJ, Fancourt D, Shiba K. Place, Spirituality, and Well-Being: A Global and Multidisciplinary Approach. Can prayer during COVID-19 home confinement support psychological health after lockdowns end? A longitudinal study of UK adults. Springer International Publishing. New York, USA. 2023; 143-162.

    Read At: Custom
  • Published on 9/29/2023

    Hikichi H, Shiba K, Aida J, Kondo K, Kawachi I. Association between sense of coherence and health and well-being among older survivors of a natural disaster: a prospective outcome-wide study. Sci Rep. 2023 Sep 29; 13(1):16385. PMID: 37773258.

    Read At: PubMed
  • Published on 8/28/2023

    Li J, Shirai K, Okuzono SS, Shiba K, Kondo K, Kawachi I, Iso H. Sense of Coherence and Incident Dementia in Older Japanese Adults: The Japan Gerontological Evaluation Study. J Am Med Dir Assoc. 2024 Feb; 25(2):225-231.e6. PMID: 37652088.

    Read At: PubMed
  • Published on 8/11/2023

    Kino S, Tamada Y, Takeuchi K, Nakagomi A, Shiba K, Kusama T, Yamamoto T, Aida J. Exploring the relationship between oral health and multiple health conditions: An outcome-wide approach. J Prosthodont Res. 2023 Aug 11. PMID: 37574274.

    Read At: PubMed

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