Recommendations for quantitative cerebral perfusion MRI using multi-timepoint arterial spin labeling: Acquisition, quantification, and clinical applications.

Accurate assessment of cerebral perfusion is vital for understanding the hemodynamic processes involved in various neurological disorders and guiding clinical decision-making. This guidelines article provides a comprehensive overview of quantitative perfusion imaging of the brain using multi-timepoint arterial spin labeling (ASL), along with recommendations for its acquisition and quantification. A major benefit of acquiring ASL data with multiple label durations and/or post-labeling delays (PLDs) is being able to account for the effect of variable arterial transit time (ATT) on quantitative perfusion values and additionally visualize the spatial pattern of ATT itself, providing valuable clinical insights. Although multi-timepoint data can be acquired in the same scan time as single-PLD data with comparable perfusion measurement precision, its acquisition and postprocessing presents challenges beyond single-PLD ASL, impeding widespread adoption. Building upon the 2015 ASL consensus article, this work highlights the protocol distinctions specific to multi-timepoint ASL and provides robust recommendations for acquiring high-quality data. Additionally, we propose an extended quantification model based on the 2015 consensus model and discuss relevant postprocessing options to enhance the analysis of multi-timepoint ASL data. Furthermore, we review the potential clinical applications where multi-timepoint ASL is expected to offer significant benefits. This article is part of a series published by the International Society for Magnetic Resonance in Medicine (ISMRM) Perfusion Study Group, aiming to guide and inspire the advancement and utilization of ASL beyond the scope of the 2015 consensus article.

ASL lexicon and reporting recommendations: A consensus report from the ISMRM Open Science Initiative for Perfusion Imaging (OSIPI).

The 2015 consensus statement published by the International Society for Magnetic Resonance in Medicine (ISMRM) Perfusion Study Group and the European Cooperation in Science and Technology ( COST) Action ASL in Dementia aimed to encourage the implementation of robust arterial spin labeling (ASL) perfusion MRI for clinical applications and promote consistency across scanner types, sites, and studies. Subsequently, the recommended 3D pseudo-continuous ASL sequence has been implemented by most major MRI manufacturers. However, ASL remains a rapidly and widely developing field, leading inevitably to further divergence of the technique and its associated terminology, which could cause confusion and hamper research reproducibility. On behalf of the ISMRM Perfusion Study Group, and as part of the ISMRM Open Science Initiative for Perfusion Imaging (OSIPI), the ASL Lexicon Task Force has been working on the development of an ASL Lexicon and Reporting Recommendations for perfusion imaging and analysis, aiming to (1) develop standardized, consensus nomenclature and terminology for the broad range of ASL imaging techniques and parameters, as well as for the physiological constants required for quantitative analysis; and (2) provide a community-endorsed recommendation of the imaging parameters that we encourage authors to include when describing ASL methods in scientific reports/papers. In this paper, the sequences and parameters in (pseudo-)continuous ASL, pulsed ASL, velocity-selective ASL, and multi-timepoint ASL for brain perfusion imaging are included. However, the content of the lexicon is not intended to be limited to these techniques, and this paper provides the foundation for a growing online inventory that will be extended by the community as further methods and improvements are developed and established.

Effects of disaster-related traumatic events on worry about radiation and COVID-19: A decade after the Fukushima nuclear power plant accident.

Community residents exposed to nuclear power plant (NPP) accidents have long-term worry about the effects of radiation. After the 2011 Fukushima NPP accident, those who experienced traumatic events during the Great East Japan Earthquake (GEJE) tended to have greater worry about radiation. Along with the prolonged worry about radiation, there may also be cognitive changes caused by the traumatic events. We hypothesized that if there were cognitive changes underlying the prolonged worry about radiation, those who experienced the traumatic events would tend to have greater worry about other issues unrelated to radiation. We examined the effects of the traumatic events during the GEJE on community residents' worry about radiation and COVID-19 a decade after the Fukushima NPP accident. Using the data of a longitudinal questionnaire survey following a random sample of 4900 community residents outside the evacuation zone in Fukushima, this study analyzed 774 responses (15.8%). The traumatic events consisted of (1) injury, (2) injury or death of a family member, and (3) the loss of a house or other property. We developed a mediation model drawing paths from the traumatic events to worry about radiation and COVID-19, including posttraumatic stress symptoms (PTSS) as a mediator, using structural equation modeling. The traumatic events directly affected worry about radiation. Although it did not directly affect worry about COVID-19, it did so indirectly through worry about radiation and PTSS. Traumatic events can increase trauma-related worry independently of PTSS and increase trauma-unrelated worry indirectly through trauma-related worry and PTSS.

Psychological burden predicts new-onset diabetes in men: A longitudinal observational study in the Fukushima Health Management Survey after the Great East Japan earthquake.

Background: The burden of psychological distress and post-traumatic stress disorder (PTSD) has been suggested as a factor in developing type 2 diabetes mellitus. However, longitudinal features in psychological distress- and PTSD-related new-onset diabetes mellitus have not been thoroughly evaluated. Methods: The association between probable depression and probable PTSD and the risk of developing new-onset diabetes mellitus was evaluated in a 7-year prospective cohort of evacuees of the Great East Japan Earthquake in 2011. Probable depression was defined as a Kessler 6 scale (K6) ≥ 13 and probable PTSD as a PTSD Checklist-Stressor-Specific Version (PCL-S) ≥ 44. Results: The log-rank test for the Kaplan-Meier curve for new-onset diabetes mellitus was significant between K6 ≥ 13 vs. < 13 and PCL-S ≥ 44 vs. < 44 in men but not in women. In men, both K6 ≥ 13 and PCL-S ≥ 44 remained significant in the Cox proportional hazards model after multivariate adjustment for established risk factors and disaster-related factors, including evacuation, change in work situation, sleep dissatisfaction, and education. Conclusion: The post-disaster psychological burden of probable depression and probable PTSD was related to new-onset diabetes in men but not in women. In post-disaster circumstances, prevention strategies for new-onset diabetes might consider sex differences in terms of psychological burden.

Worry about Radiation and Its Risk Factors Five to Ten Years after the Fukushima Nuclear Power Plant Disaster.

Worry about radiation persists long after nuclear power plant accidents. Young age, low socioeconomic status, being married, and disaster-related experiences are known to be associated with greater worry about radiation. This study explored the duration of the effects of these risk factors on worry about radiation after the 2011 Fukushima nuclear power plant accident, using the longitudinal data of randomly sampled non-evacuee community residents who were followed five to ten years after the accident. Questionnaire surveys were conducted five times with 1825 respondents (37.2% of the 4900 initial targets). We examined the interaction of time and risk factors of worry about radiation using a mixed model. Fear or anxiety immediately after the accident had effects on worry about radiation that continued even after 10 years, though it slightly attenuated with time. Family problems stemming from the disaster retained their effects. While direct damage and evacuation experience were significantly associated with worry about radiation in the early phase, their effects diminished and became non-significant during the study period. Being under the age of 65, having low educational attainment, and being married were significantly associated with worry about radiation, although the association with age weakened over time. Individuals who experience intense fear or anxiety post-nuclear power plant accidents or disaster-related family problems may need continuous monitoring for their worry about radiation even 10 years after such accidents.

Dietary Patterns and New-Onset Type 2 Diabetes Mellitus in Evacuees after the Great East Japan Earthquake: A 7-Year Longitudinal Analysis in the Fukushima Health Management Survey.

Background: Dietary patterns may be linked to the incidence of type 2 diabetes mellitus (T2DM) after disasters. We investigated the association between dietary patterns and new-onset T2DM in evacuees of the Great East Japan Earthquake and the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Methods: Among the 22,740 non-diabetic participants aged 20-89 years who completed the dietary assessment in the Fukushima Health Management Survey between July 2011 and November 2012, the incidence of T2DM was evaluated until 2018. Principal component analysis with varimax rotation was applied to derive dietary patterns based on a validated, short-form food frequency questionnaire. The identified dietary patterns were categorized as typical Japanese, juice, and meat. Results: The cumulative incidence of T2DM was 18.0 and 9.8 per 1000 person-years in men and women, respectively, during the follow-up period. The multiple-adjusted hazard ratio (95% confidence interval) of the highest vs. lowest quartile of the typical Japanese pattern scores for T2DM was 0.80 (0.68, 0.94; P for trend = 0.015) in total, 0.85 (0.68, 1.06; P for trend = 0.181) in men, and 0.76 (0.60, 0.95; P for trend = 0.04) in women. Conclusions: A typical Japanese dietary pattern may be associated with a reduced new-onset T2DM risk in evacuees, especially women, after the Great East Japan Earthquake and the FDNPP accident.

Recent Technical Developments in ASL: A Review of the State of the Art.

This review article provides an overview of a range of recent technical developments in advanced arterial spin labeling (ASL) methods that have been developed or adopted by the community since the publication of a previous ASL consensus paper by Alsop et al. It is part of a series of review/recommendation papers from the International Society for Magnetic Resonance in Medicine Perfusion Study Group. Here, we focus on advancements in readouts and trajectories, image reconstruction, noise reduction, partial volume correction, quantification of nonperfusion parameters, fMRI, fingerprinting, vessel selective ASL, angiography, deep learning, and ultrahigh field ASL. We aim to provide a high level of understanding of these new approaches and some guidance for their implementation, with the goal of facilitating the adoption of such advances by research groups and by MRI vendors. Topics outside the scope of this article that are reviewed at length in separate articles include velocity selective ASL, multiple-timepoint ASL, body ASL, and clinical ASL recommendations.

Planning of gamma knife radiosurgery (GKR) for brain arteriovenous malformations using triple magnetic resonance angiography (triple-MRA).

PURPOSE: Intra-arterial Digital Subtraction Angiography (DSA) is the gold standard technique for radiosurgery target delineation in brain Arterio-Venous Malformations (AVMs). This study aims to evaluate whether a combination of three Magnetic Resonance Angiography sequences (triple-MRA) could be used for delineation of brain AVMs for Gamma Knife Radiosurgery (GKR). METHODS: Fifteen patients undergoing DSA for GKR targeting of brain AVMs also underwent triple-MRA: 4D Arterial Spin Labelling based angiography (ASL-MRA), Contrast-Enhanced Time-Resolved MRA (CE-MRA) and High Definition post-contrast Time-Of-Flight angiography (HD-TOF). The arterial phase of the AVM nidus was delineated on triple-MRA by an interventional neuroradiologist and a consultant neurosurgeon (triple-MRA volume). Triple-MRA volumes were compared to AVM targets delineated by the clinical team for delivery of GKR using the current planning paradigm, i.e., stereotactic DSA and volumetric MRI (DSA volume). Difference in size, degree of inclusion (DI) and concordance index (CcI) between DSA and triple-MRA volumes are reported. RESULTS: AVM target volumes delineated on triple-MRA were on average 9.8% smaller than DSA volumes (95%CI:5.6-13.9%; SD:7.14%; p = .003). DI of DSA volume in triple-MRA volume was on average 73.5% (95%CI:71.2-76; range: 65-80%). The mean percentage of triple-MRA volume not included on DSA volume was 18% (95%CI:14.7-21.3; range: 7-30%). CONCLUSION: The technical feasibility of using triple-MRA for visualisation and delineation of brain AVMs for GKR planning has been demonstrated. Tighter and more precise delineation of AVM target volumes could be achieved by using triple-MRA for radiosurgery targeting. However, further research is required to ascertain the impact this may have in obliteration rates and side effects.

3-day intervention program for family members of hikikomori sufferers: A pilot randomized controlled trial.

Backgrounds: Hikikomori, pathological social withdrawal, is becoming a crucial mental health issue in Japan and worldwide. We have developed a 3-day family intervention program for hikikomori sufferers based on Mental Health First Aid (MHFA) and Community Reinforcement and Family Training (CRAFT). This study aims to confirm the effectiveness of the 3-day program by a randomized controlled trial. Methods: This study was registered on the UMIN Clinical Trials Registry (UMIN000037289). Fifteen parents were assigned to the treat as usual (TAU) group (TAU only; Age Mean, 65.6; SD, 7.8), and 14 to the Program group (program + TAU; Age Mean, 67.9; SD, 8.6). This study was discontinued due to the COVID-19 pandemic; the recruitment rate was 36.3% of our target sample size of 80. Results: Perceived skills improved temporally and stigma temporally worsened in the TAU group. Confidence decreased and attitude showed no change in both groups. Aggressive behaviors of hikikomori sufferers were significantly worsened in the Program group; however, no serious domestic violence was reported. In the TAU group, Avoidance and irregular life patterns were improved. Activity levels were worsened in both groups. Two participants (16.7%) in the Program group and one participant (7.7%) in the TAU group reported actual behavioral changes (e.g., utilizing support). Conclusion: We could not draw general conclusions on the effectiveness of the program due to the study discontinuation. Nevertheless, this study indicates the necessity for revision of the program to improve family members' confidence in engaging with hikikomori sufferers, with safer approaching by families.

Suboptimal diabetic control and psychological burden after the triple disaster in Japan: the Fukushima Health Management Survey.

INTRODUCTION: A triple disaster struck eastern Japan in March 2011. We investigated the psychological distress and post-traumatic stress disorder (PTSD) symptoms caused by the disaster in people without or with diabetes mellitus. RESEARCH DESIGN AND METHODS: This cross-sectional analysis examined the 16 097 evacuees (1820 (11.3%) with and 14 277 (88.7%) without diabetes mellitus) included in the Fukushima Health Management Survey. Non-specific mental health distress was assessed using the Kessler-6 Scale, and traumatic symptoms were evaluated using the PTSD Checklist. Logistic regression analyses were used to estimate the OR and 95% CI associated with symptoms, adjusted for diabetes-related and disaster-related factors. RESULTS: In the age-adjusted and sex-adjusted logistic models, suboptimal diabetic control (hemoglobin A1c (HbA1c) ≥7%) was associated with both psychological distress and possible PTSD. In the same models, current smoking, evacuation, and sleep dissatisfaction were associated with psychological distress and possible PTSD. In the multivariate-adjusted logistic models, HbA1c ≥7% was associated with psychological distress, independent of job change, evacuation, or sleep dissatisfaction. CONCLUSION: After the triple disaster, non-specific mental health distress was associated with suboptimal diabetic control. Thus, patients with diabetes, especially those with suboptimal diabetic control, may be vulnerable to postdisaster psychological burden.

The ongoing activities of livelihood support counselors following nuclear disaster under the COVID-19 restrictions: A preliminary survey.

BACKGROUND: This preliminary study aims to understand the state of support provided in the evacuation areas of the 2011 Fukushima nuclear disaster, during the novel coronavirus 2019 (COVID-19) restriction. METHODS: A self-administered survey was conducted with 18 livelihood support counselors from two Social Welfare Councils in November 2020. We investigated the number of consultations since the COVID-19 pandemic and the impact of telephonic consultation as opposed to in-person consultations through visits to counselees' homes. RESULTS: Counselors have been continued offering supports to their counselees even under the COVID-19 restrictions, in fact, fifty percent of counselors have increased the consultations. Although some counselors had a sense of unease or concern about telephonic consultation due to the inability to see their non-verbal expressions, there were some advantages of telephonic consultation, in that the counselors were able to have longer sessions and listen more attentively to severe issues. CONCLUSIONS: Notably, livelihood support counselors in this study have increased the number of consultations while utilization telephonic consultations, despite the adverse conditions created by the COVID-19 restriction. Moreover, certain advantages of telephonic consultation instead of in-person consultation have been identified. It may be an effective support method avoiding in-person contacts, that also considers infection-prevention measures.

Socioeconomic status, damage-related conditions, and PTSD following the Fukushima-daiichi nuclear power plant accident:The Fukushima Health Management Survey.

The Great East Japan Earthquake severely damaged the Tohoku and Kanto districts, and Fukushima Prefecture faced a subsequent nuclear disaster. Few studies have reported the effects of socioeconomic stressors on individuals' mental status following disasters. We analyzed the responses of 60,704 adult residents of a designated restricted area to the PTSD Checklist-Stressor-Specific Version (PCL-S). The relationships between the PCL-S scores and demographic, socioeconomic, and damage-related variables were analyzed using regression analysis to predict participants' severity of PTSD symptoms. Approximately 14.1% of evacuees had severe PTSD symptoms (PCL-S ≥50) eighteen months post-earthquake. The PCL-S scores were higher among women, older adults, less educated people, those with a history of mental illness, and those living outside Fukushima Prefecture. The PCL-S scores increased with participants' scores on the Kessler Psychological Distress Scale. The number of trauma-exposure stressors and socioeconomic stressors were associated with 1.52 and 3.77 increases in the PCL-S score, respectively. Furthermore, psychological distress, unemployment, decreased income, house damage, tsunami experience, nuclear power plant accident experience, and loss of someone close due to the disaster were associated with the prevalence of severe PTSD symptoms. The complex triple disaster of a major earthquake, tsunami, and nuclear accident created significant socioeconomic changes that may be important determinants of PTSD among residents of restricted access areas in Fukushima.

Effectiveness of suicide prevention gatekeeper training for university teachers in Japan.

Suicide is a leading cause of death among Japanese college and university students. Our previous study showed that the gatekeeper training (GKT) program significantly improved competence and confidence in the management of suicidal students in university administrative staff. However, we could not determine which component of the program was effective, nor if this program was effective for university teachers as well. In the current study, 81 university teachers were recruited; 63 of them received a general mental health lecture (MHL) and 18 of them received a 2.5 -h GKT program based on the Mental Health First Aid program. Competence and confidence in managing suicide intervention and behavioral intention as a gatekeeper were assessed by a self-report questionnaire before and immediately after the intervention. As a result, we found a significant improvement in competence in the management of suicidal students in the GKT group compared to the MHL group. We also found significant improvements in confidence in the management of suicidal students and behavioral intention as gatekeepers in the GKT group, although the questionnaires for these outcomes were not validated. The program satisfaction score was significantly higher in the GKT group than in the MHL group. To our knowledge, this is the first study to evaluate a GKT program for university teachers in Japan. By comparing the two groups, we explicitly confirmed that active involvement of the participants is crucial for effective suicide prevention training.

Factors Hindering Social Participation among Older Residents from Evacuation Zones after the Nuclear Power Plant Accident in Fukushima: The Fukushima Health Management Survey.

Considering the health effects of radiation accompanying the nuclear power plant accident that occurred in the wake of the Great East Japan Earthquake, this study aimed to examine social participation after the disaster and factors hindering participation among citizens aged ≥ 65 years from designated evacuation zones inside the Fukushima prefecture. The target population comprised 180,604 residents in 13 municipalities containing designated evacuation zones. There were 73,433 valid responses (response rate, 40.7%); of which, data from 19,573 respondents aged ≥ 65 years were analyzed. Multinomial logistic regression analyses were conducted to investigate the factors associated with social participation. In total, 53.0% of older evacuees did not participate in recreational activities or communal services. Stratified analysis showed that living outside the Fukushima prefecture and requiring assistance with activities of daily living were associated with low social participation. This study clarified that the majority of older evacuees did not participate in social activities at the time of the survey within one year of the disaster. Furthermore, where these older individuals were evacuated to and whether they were able to live independently might have affected their social participation. Better subjective health, better sleep quality, and more frequent exercise may be associated with improved social participation.

Evacuation after the Great East Japan Earthquake is an independent factor associated with hyperuricemia: The Fukushima Health Management Survey.

BACKGROUND AND AIMS: On March 11, 2011, the Great East Japan Earthquake occurred in Japan, with a nuclear accident subsequently occurring at the Fukushima Daiichi Nuclear Power Plant. The disaster forced many evacuees to change particular aspects of their lifestyles. This study assessed the association between evacuation and hyperuricemia based on the Fukushima Health Management Survey from a lifestyle and socio-psychological perspective. METHODS AND RESULTS: This cross-sectional study included 22,812 residents (9391 men and 13,297 women) who underwent both the Comprehensive Health Check and the Mental Health and Lifestyle Survey in fiscal year 2011. Associations between hyperuricemia and lifestyle- and disaster-related factors including evacuation were estimated using a logistic and liner regression analysis. With hyperuricemia defined as uric acid levels >7.0 mg/dL for men and >6.0 mg/dL for women, significant associations were observed between evacuation and hyperuricemia in men (the multivariate-adjusted odds ratio 1.20, 95% confidence interval, 1.05-1.36, p = 0.005), but not in women. In the multivariate-adjusted multiple liner regression analysis, evacuation had significant and positive associations with uric acid levels both in men (ß = 0.084, p = 0.002) and women (ß = 0.060, p < 0.001). CONCLUSION: Evacuation after a natural disaster is an independent factor associated with hyperuricemia.

Association between post-traumatic stress disorder symptoms and bone fractures after the Great East Japan Earthquake in older adults: a prospective cohort study from the Fukushima Health Management Survey.

BACKGROUND: It has been reported that psychological stress affects bone metabolism and increases the risk of fracture. However, the relationship between bone fractures and post-traumatic stress disorder (PTSD) is unclear. This study aimed to evaluate the effects of disaster-induced PTSD symptoms on fracture risk in older adults. METHODS: This study evaluated responses from 17,474 individuals aged ≥ 65 years without a history of fractures during the Great East Japan Earthquake who answered the Mental Health and Lifestyle Survey component of the Fukushima Health Management Survey conducted in 2011. The obtained data could determine the presence or absence of fractures until 2016. Age, sex, physical factors, social factors, psychological factors, and lifestyle factors were subsequently analyzed. Survival analysis was then performed to determine the relationship between the fractures and each factor. Thereafter, univariate and multivariate Cox proportional hazard models were constructed to identify fracture risk factors. RESULTS: In total, 2,097 (12.0%) fractures were observed throughout the follow-up period. Accordingly, univariate and multivariate Cox proportional hazard models showed that PTSD symptoms (total PTSD checklists scoring ≥ 44) [hazard ratio (HR): 1.26; 95% confidence interval (CI): 1.10-1.44; P = 0.001], history of cancer (HR: 1.49; 95% CI: 1.24-1.79; P < 0.001), history of stroke (HR: 1.25; 95% CI: 1.03-1.52; P = 0.023), history of heart disease (HR: 1.30; 95% CI: 1.13-1.50; P < 0.001), history of diabetes (HR: 1.23; 95% CI: 1.09-1.39; P < 0.001), current smoking (HR: 1.29; 95% CI: 1.02-1.63; P = 0.036), and high dissatisfaction with sleep or no sleep at all (HR: 1.33; 95% CI: 1.02-1.74; P = 0.035) promoted a significant increase in fracture risk independent of age and sex. CONCLUSIONS: The present study indicates that disaster-induced PTSD symptoms and insomnia contribute to increased fracture risk among older adults residing in evacuation areas within the Fukushima Prefecture.

Distrust in government and its relationship with mental health after the Fukushima nuclear power plant accident.

BACKGROUND: Distrust in authorities has negative effects on mental health. AIMS: In this study, we aimed to explore whether the impact of distrust in government on mental health became stronger in the area heavily affected by the 2011 Fukushima nuclear power plant accident. METHODS: We examined the effects of distrust in the national government on depressive symptoms three years after the accident among community residents in Fukushima prefecture using those in the Kanto area (the area surrounding Tokyo) as a control. A questionnaire survey was administered to a random sample of 1000 residents in Fukushima prefecture and 1650 residents in the Kanto area. Distrust in the national government was assessed using a four-point single-item scale. Depressive symptoms were measured using the Patient Health Questionnaire-9. The associations of residential area (i.e. living in Fukushima prefecture or in the Kanto area) and distrust in the national government with depressive symptoms were examined, controlling for socio-demographic characteristics and disaster-related experiences using multivariate linear regression analyses. We used the interaction term of residential area and distrust in the government to explore the difference in the association between the respondents in Fukushima prefecture and those in the Kanto area. RESULTS: Valid responses were obtained from 976 (36.8%) residents. Distrust in the government was associated with depressive symptoms and the association was stronger in Fukushima prefecture than in the Kanto area. CONCLUSION: The deleterious effects of distrust in the government on mental health may become more serious after a nuclear power plant accident and require careful attention during support activities in an affected area.

Analysis of direction of association between radiation risk perception and relocation using a random-intercept and cross lagged panel model: The Fukushima Health Management Survey.

In the aftermath of a nuclear disaster, a person's radiation risk perception can harm their sociopsychological health. Although there are reports of an association between radiation risk perception and relocation, the direction of this association has not been clarified yet. In this study, we used a random-intercept and cross lagged panel model (RI-CLPM) to investigate the association and its direction between radiation risk perception and the prefectural-level relocation (i.e., inside/outside of Fukushima Prefecture). We did this by using five waves of longitudinal surveys between 2011 fiscal year and 2015 fiscal year among the people affected by the Fukushima disaster in 2011. We included 90,567 participants aged ≥15 years during the time of the disaster who responded to the questionnaire at least once. RI-CLPM was applied to examine the reciprocal relationship between radiation risk perception and locations. We used two radiation risk perception indicators (i.e., genetic effect and delayed effect) and two handling methods on missing data (i.e., listwise deletion and full information maximum likelihood estimation) as sensitive analyses. The effects of radiation risk perception on relocation were found to be negligibly small. Living inside Fukushima Prefecture reduced radiation risk perception irrespective of the difference of indicators or methods, highlighting that radiation risk perception did not dominantly govern whether people were living inside Fukushima Prefecture, but that the locations also affected radiation risk perception. This was the first study to reveal the direction of the association between radiation risk perception and relocation in the aftermath of nuclear disasters.

Association between Psychological Factors and Evacuation Status and the Incidence of Cardiovascular Diseases after the Great East Japan Earthquake: A Prospective Study of the Fukushima Health Management Survey.

Evidence regarding the effect of psychological factors and evacuation on cardiovascular disease occurrence after large-scale disasters is limited. This prospective study followed up a total of 37,810 Japanese men and women aged 30-89 years from the Fukushima Prefecture with no history of stroke or heart disease at baseline (2012), until 2017. This period included 3000 cardiovascular events recorded through questionnaires and death certificates. The participants' psychological distress, trauma reaction, and evacuation status were defined, and divided into four groups based on combinations of psychological factors and evacuation status. We calculated the hazard ratios and 95% confidence intervals for only psychological, only evacuation, or both of them compared with neither using Cox proportional hazard models. Psychological factors along with evacuation resulted in approximately 5% to 25% higher magnitude of stroke and heart disease risk than psychological factors only among men. Compared to neither, the multivariable hazard ratios of those with both psychological distress and evacuation were 1.75 for stroke and 1.49 for heart disease, and those of both trauma reaction and evacuation were 2.01 and 1.57, respectively, among men. Evacuation combined with psychological factors increased the risk of stroke and heart disease risks especially in men after the Great East Japan Earthquake.