What factors are associated with new social isolation years after the great East Japan Earthquake?: findings from the TMM CommCohort study

Abstract Background The effects of disaster experiences on social isolation and related factors remain unclear. Using longitudinal data, this study aimed to identify new social isolation and its associated factors after the Great East Japan Earthquake (GEJE), which occurred on March 11, 2011. Method...

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Main Authors: Yuka Kotozaki, Kozo Tanno, Kotaro Otsuka, Ryohei Sasaki, Makoto Sasaki
Format: Article
Language:English
Published: BMC 2025-08-01
Series:BMC Public Health
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Online Access:https://doi.org/10.1186/s12889-025-23778-x
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author Yuka Kotozaki
Kozo Tanno
Kotaro Otsuka
Ryohei Sasaki
Makoto Sasaki
author_facet Yuka Kotozaki
Kozo Tanno
Kotaro Otsuka
Ryohei Sasaki
Makoto Sasaki
author_sort Yuka Kotozaki
collection DOAJ
description Abstract Background The effects of disaster experiences on social isolation and related factors remain unclear. Using longitudinal data, this study aimed to identify new social isolation and its associated factors after the Great East Japan Earthquake (GEJE), which occurred on March 11, 2011. Methods We analyzed longitudinal data from 12,795 participants who responded to self-report questionnaires, utilizing the Lubben Social Network Scale-6 (LSNS-6). Participants included 4,450 men and 8,345 women; the sex ratio of the analytic sample was broadly consistent with that of the study population at baseline. Baseline data were collected between fiscal years (FY) 2013 and 2015, and follow-up data were collected between FY2017 and FY2019. Social isolation was defined as a score < 12 on the LSNS-6. Based on their level of social isolation in the second survey, participants were categorized into two groups: not socially isolated and newly socially isolated. To examine factors associated with new social isolation, we used logistic regression analysis to calculate multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the newly socially isolated group versus the not socially isolated group by sex. Results New social isolation was associated with several lifestyle and psychosocial factors, exhibiting differences between men and women. Among men, factors associated with new social isolation were not currently smoking among those without house damage, living alone among those with house damage, and no exercise habits among those who experienced the death of family members due to GEJE. Among women who lost family members due to GEJE, insomnia was associated with new social isolation. Conclusion The occurrence of new social isolation years after the GEJE and its associated factors varied by sex and the presence of GEJE-related damages. To prevent new social isolation in the aftermath of a large-scale natural disaster, it is crucial to consider sex-specific factors contributing to social isolation.
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spelling doaj-art-0b24b2f5e2cf4087836cfc1c6b0d24522025-08-20T03:06:27ZengBMCBMC Public Health1471-24582025-08-0125111210.1186/s12889-025-23778-xWhat factors are associated with new social isolation years after the great East Japan Earthquake?: findings from the TMM CommCohort studyYuka Kotozaki0Kozo Tanno1Kotaro Otsuka2Ryohei Sasaki3Makoto Sasaki4Iwate Tohoku Medical Megabank Organization, Iwate Medical UniversityIwate Tohoku Medical Megabank Organization, Iwate Medical UniversityIwate Tohoku Medical Megabank Organization, Iwate Medical UniversityDivision of Physical Education, Department of Human Sciences, Iwate Medical University Center for Liberal Arts and SciencesIwate Tohoku Medical Megabank Organization, Iwate Medical UniversityAbstract Background The effects of disaster experiences on social isolation and related factors remain unclear. Using longitudinal data, this study aimed to identify new social isolation and its associated factors after the Great East Japan Earthquake (GEJE), which occurred on March 11, 2011. Methods We analyzed longitudinal data from 12,795 participants who responded to self-report questionnaires, utilizing the Lubben Social Network Scale-6 (LSNS-6). Participants included 4,450 men and 8,345 women; the sex ratio of the analytic sample was broadly consistent with that of the study population at baseline. Baseline data were collected between fiscal years (FY) 2013 and 2015, and follow-up data were collected between FY2017 and FY2019. Social isolation was defined as a score < 12 on the LSNS-6. Based on their level of social isolation in the second survey, participants were categorized into two groups: not socially isolated and newly socially isolated. To examine factors associated with new social isolation, we used logistic regression analysis to calculate multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the newly socially isolated group versus the not socially isolated group by sex. Results New social isolation was associated with several lifestyle and psychosocial factors, exhibiting differences between men and women. Among men, factors associated with new social isolation were not currently smoking among those without house damage, living alone among those with house damage, and no exercise habits among those who experienced the death of family members due to GEJE. Among women who lost family members due to GEJE, insomnia was associated with new social isolation. Conclusion The occurrence of new social isolation years after the GEJE and its associated factors varied by sex and the presence of GEJE-related damages. To prevent new social isolation in the aftermath of a large-scale natural disaster, it is crucial to consider sex-specific factors contributing to social isolation.https://doi.org/10.1186/s12889-025-23778-xSocial isolationRelated factorsDamage situationCommunity-based cohort study
spellingShingle Yuka Kotozaki
Kozo Tanno
Kotaro Otsuka
Ryohei Sasaki
Makoto Sasaki
What factors are associated with new social isolation years after the great East Japan Earthquake?: findings from the TMM CommCohort study
BMC Public Health
Social isolation
Related factors
Damage situation
Community-based cohort study
title What factors are associated with new social isolation years after the great East Japan Earthquake?: findings from the TMM CommCohort study
title_full What factors are associated with new social isolation years after the great East Japan Earthquake?: findings from the TMM CommCohort study
title_fullStr What factors are associated with new social isolation years after the great East Japan Earthquake?: findings from the TMM CommCohort study
title_full_unstemmed What factors are associated with new social isolation years after the great East Japan Earthquake?: findings from the TMM CommCohort study
title_short What factors are associated with new social isolation years after the great East Japan Earthquake?: findings from the TMM CommCohort study
title_sort what factors are associated with new social isolation years after the great east japan earthquake findings from the tmm commcohort study
topic Social isolation
Related factors
Damage situation
Community-based cohort study
url https://doi.org/10.1186/s12889-025-23778-x
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