Uncovering Heterogeneous Associations Between Disaster-Related Trauma and Subsequent Functional Limitations: A...

Area of Science:

• Gerontology
• Disaster Medicine
• Public Health

Background:

• The 2011 Great East Japan Earthquake caused widespread destruction, displacing many older adults.
• Understanding the long-term health consequences, specifically functional limitations, is crucial for disaster preparedness and response.

Purpose of the Study:

• To examine the heterogeneity in the association between disaster-related home loss and functional limitations in older adults.
• To identify characteristics of subpopulations most vulnerable to functional decline after experiencing home loss.

Main Methods:

• Prospective cohort study of Japanese older adults surviving the 2011 earthquake.
• Objective assessment of complete home loss and longitudinal assessment of physical disability, activities of daily living (ADL), and instrumental activities of daily living (IADL).
• Advanced statistical methods including targeted maximum likelihood estimation with SuperLearning and generalized random forest for analyzing effect heterogeneity, adjusting for 55 baseline characteristics.

Main Results:

• Home loss was consistently associated with increased functional limitations on average.
• Significant heterogeneity in this association was observed across different outcomes.
• Vulnerable subgroups included older, unmarried, non-working individuals living alone with pre-existing health conditions; lower education with higher income also indicated vulnerability for some outcomes.

Conclusions:

• Disaster-related home loss has a complex and heterogeneous impact on the functional status of older adults.
• Identifying vulnerable subgroups is essential for targeted interventions and support in post-disaster recovery efforts.
• Machine learning approaches effectively uncover complex heterogeneity in health outcomes following major disasters.