Causal Inference in Studying the Long-Term Health Effects of Disasters: Challenges and Potential Solutions.

Two frequently encountered but underrecognized challenges for causal inference in studying the long-term health effects of disasters among survivors include 1) time-varying effects of disasters on a time-to-event outcome and 2) selection bias due to selective attrition. In this paper, we review approaches for overcoming these challenges and demonstrate application of the approaches to a real-world longitudinal data set of older adults who were directly affected by the 2011 Great East Japan Earthquake and Tsunami (n = 4,857). To illustrate the problem of time-varying effects of disasters, we examined the association between degree of damage due to the tsunami and all-cause mortality. We compared results from Cox regression analysis assuming proportional hazards with those derived using adjusted parametric survival curves allowing for time-varying hazard ratios. To illustrate the problem of selection bias, we examined the association between proximity to the coast (a proxy for housing damage from the tsunami) and depressive symptoms. We corrected for selection bias due to attrition in the 2 postdisaster follow-up surveys (conducted in 2013 and 2016) using multivariable adjustment, inverse probability of censoring weighting, and survivor average causal effect estimation. Our results demonstrate that analytical approaches which ignore time-varying effects on mortality and selection bias due to selective attrition may underestimate the long-term health effects of disasters.

Study Profile of the Tohoku Medical Megabank Community-Based Cohort Study.

BACKGROUND: We established a community-based cohort study to assess the long-term impact of the Great East Japan Earthquake on disaster victims and gene-environment interactions on the incidence of major diseases, such as cancer and cardiovascular diseases. METHODS: We asked participants to join our cohort in the health check-up settings and assessment center based settings. Inclusion criteria were aged 20 years or over and living in Miyagi or Iwate Prefecture. We obtained information on lifestyle, effect of disaster, blood, and urine information (Type 1 survey), and some detailed measurements (Type 2 survey), such as carotid echography and calcaneal ultrasound bone mineral density. All participants agreed to measure genome information and to distribute their information widely. RESULTS: As a result, 87,865 gave their informed consent to join our study. Participation rate at health check-up site was about 70%. The participants in the Type 1 survey were more likely to have psychological distress than those in the Type 2 survey, and women were more likely to have psychological distress than men. Additionally, coastal residents were more likely to have higher degrees of psychological distress than inland residents, regardless of sex. CONCLUSION: This cohort comprised a large sample size and it contains information on the natural disaster, genome information, and metabolome information. This cohort also had several detailed measurements. Using this cohort enabled us to clarify the long-term effect of the disaster and also to establish personalized prevention based on genome, metabolome, and other omics information.

Seismic preparedness of families with children: Measures and dynamics.

Earthquakes are unpredictable events, thus seismic preparedness of households should be fostered, considering the specific needs of each family. Children, for example, are particularly vulnerable to disasters and to the effects of their consequences, but can also act as promoters of preparedness within families. Being part of a wider research, this qualitative study intends to better understand seismic preparedness within families with children in S. Miguel, the largest and most populated island of the volcanic archipelago of the Azores. Two semi-structured interviews were conducted. The first interview was conducted with 125 family representatives, addressing their current preparedness measures. From these representatives, 105 families that had non-existent or insufficient preparedness were selected for a second interview. In the time between the two interviews, the families were instructed to develop seismic preparedness measures. The process of development of these measures was also assessed. Data were analysed using content analysis and frequency analysis. Results point to low levels of preparedness, both at the time of the initial interview and developed subsequently, and families adopted few preparedness measures specifically targeting their children's needs. The results highlight, therefore, that household seismic preparedness should be promoted, with clear indications regarding preparedness specifically for families with children.

Social capital, policy fairness, and subjective life satisfaction of earthquake survivors in Wenchuan, China: a longitudinal study based on post-earthquake survey data.

BACKGROUND: Existing research has rarely examined an earthquake's sustained impact and the trajectory of the earthquake survivors' life satisfaction over time. This study aims to analyze longitudinal changes in life satisfaction of Wenchuan earthquake survivors and the impact of social capital and government relief policy. METHODS: This research applied a hierarchical linear model to longitudinal survey data collected after the earthquake. The survey was divided into three waves and was collected from Deyang City and Mianyang City of Sichuan Province. A random sampling method was used; a sample of 225 participants had valid responses over three waves of the survey. RESULTS: This study found that a survivor's social capital and the perception of the fairness of government relief policy have a significant effect on the trajectory of life satisfaction post-disaster. First, the initial life satisfaction of those with high social capital was significantly higher than of those with low social capital, whilst survivors with high social capital had a lower rate of change in life satisfaction. Second, one year after the earthquake, those who felt government policy was unfair had a lower life satisfaction than those who felt it was fair. However, from the first year to the fourth year after the disaster, survivors who believed that the government policy was unfair experienced a higher rate of change in life satisfaction than those who did not. Third, the fairness of government relief policy moderates the relationship between survivors' social capital and changes in life satisfaction. A fair policy of relief can reduce the negative impact of the lack of individual social capital on life satisfaction. CONCLUSIONS: Survivors reconstruct life satisfaction through their social network and the perception of the fairness of the government's post-disaster relief policy. Therefore, to promote the improvement of life satisfaction of survivors, it is necessary to cultivate social capital and ensure fairness of the relief policy.

Health-related quality of life and post-traumatic stress disorder in inpatients injured in the Ludian earthquake: a longitudinal study.

BACKGROUND: The aim of this longitudinal study was to identify risk factors for posttraumatic stress disorder (PTSD) in inpatients injured in the Ludian earthquake and examine the relationship between PTSD symptoms and health-related quality of life (HRQoL) following the earthquake. METHODS: Three assessments were performed during an 18-month follow-up period. In total, one-hundred forty-seven inpatients of one-hundred seventy-four inpatients (85% of the initial sample) underwent all the assessments. Injured inpatients admitted to the No. 1 People's Hospital of Zhaotong City after a severe earthquake (6.5 on the Richter scale) were enrolled in the study and assessed using the Posttraumatic Stress Disorder Checklist-Civilian Version, Clinician-Administered Posttraumatic Stress Disorder Scale, and Medical Outcomes Study Short Form-36 Scale. RESULTS: At the first, third and eighteenth months after the earthquake, the prevalence rates for PTSD were 23, 14, and 7%, respectively. In a regression model, bereavement, history of major diseases, and severe injury in the earthquake were associated with severe PTSD symptoms. HRQoL was negatively correlated with PTSD symptoms. Compared to that of Chinese norms, participants' HRQoL was significantly lower in all eight HRQoL domains of the Medical Outcomes Study Short Form-36 Scale. CONCLUSIONS: The findings suggest that a substantial proportion of inpatients injured in the earthquake experienced severe PTSD symptoms and poor HRQoL. Therefore, early preventive programs and interventions should be implemented following disasters, to reduce PTSD and improve HRQoL in injured individuals.

Uplift and seismicity driven by groundwater depletion in central California.

Groundwater use in California's San Joaquin Valley exceeds replenishment of the aquifer, leading to substantial diminution of this resource and rapid subsidence of the valley floor. The volume of groundwater lost over the past century and a half also represents a substantial reduction in mass and a large-scale unburdening of the lithosphere, with significant but unexplored potential impacts on crustal deformation and seismicity. Here we use vertical global positioning system measurements to show that a broad zone of rock uplift of up to 1-3 mm per year surrounds the southern San Joaquin Valley. The observed uplift matches well with predicted flexure from a simple elastic model of current rates of water-storage loss, most of which is caused by groundwater depletion. The height of the adjacent central Coast Ranges and the Sierra Nevada is strongly seasonal and peaks during the dry late summer and autumn, out of phase with uplift of the valley floor during wetter months. Our results suggest that long-term and late-summer flexural uplift of the Coast Ranges reduce the effective normal stress resolved on the San Andreas Fault. This process brings the fault closer to failure, thereby providing a viable mechanism for observed seasonality in microseismicity at Parkfield and potentially affecting long-term seismicity rates for fault systems adjacent to the valley. We also infer that the observed contemporary uplift of the southern Sierra Nevada previously attributed to tectonic or mantle-derived forces is partly a consequence of human-caused groundwater depletion.

Physical function, post-traumatic stress disorder, and quality of life in persons with spinal cord injury caused by the Wenchuan earthquake versus nondisaster trauma: a cross-sectional modeling study.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To compare physical function, post-traumatic stress disorder (PTSD) and quality of life (QOL) between individuals with spinal cord injury (SCI) caused by the Wenchuan earthquake and individuals with SCI caused by nondisaster trauma and to explore the relationship between physical function, PTSD and QOL. SETTING: Community, Sichuan, China. METHODS: Two hundred individuals with SCI (39 caused by the Wenchuan earthquake, 161 with other traumatic etiology) were surveyed. Physical function was assessed with the Spinal Cord Independence Measure-SR, PTSD with the PTSD Checklist-C, and QOL with the World Health Organization QOL-BREF. Independent sample t-tests and rank-sum tests were used to compare the two groups. Structural equation modeling (SEM) was used to analyze the relationship between physical function, PTSD and QOL. RESULTS: QOL of the study participants was at a moderate to low level, physical function was at a medium level. The prevalence of PTSD in the group injured due to the Wenchuan earthquake was 64.1% as opposed to 10.0% in individuals with other traumatic etiology. In the SEM, earthquake-related etiology was strongly related to increased PTSD symptoms which negatively affected QOL. Earthquake-related etiology was however also associated with slightly increased physical function which was associated with better QOL and less PTSD symptoms CONCLUSIONS: Prevalence of PTSD in earthquake survivors with SCI was largely increased as compared with people with SCI of other traumatic etiology. In spite of this, the groups did not differ in QOL because of better physical function of earthquake survivors. Effective intervention for PTSD is still needed in earthquake survivors with SCI. Continuous rehabilitative measures to improve physical function and QOL in both groups are also recommended.

Characteristic activities of slow earthquakes in Japan.

Slow earthquakes are a recently discovered phenomenon that mainly occur updip and downdip of the seismogenic zones of great earthquakes along the subducting plate interface. The spatiotemporal activity of various slow earthquakes occurring in the Nankai subduction zone is characterized by along-strike heterogeneity and along-dip systematic changes. Various slow earthquakes are horizontally distributed at their own depths and along-strike segments can be observed with respect to this distribution downdip of the locked zone; however, slow and great earthquakes occur in the same depth range near the Nankai Trough and Japan Trench axes. The frequently observed spatiotemporal interactions between different slow earthquakes can be attributed to their sensitivity and the stress transfer of the surrounding areas. This stress transfer is expected to extend to the adjacent sections in the seismogenic zone. Therefore, precise monitoring of slow earthquakes is important for future evaluations of great earthquakes, which requires the long-term maintenance and continuous improvement of the high-quality observation networks.

Evaluating the Prevalence of PTSD among Children and Adolescents after Earthquakes and Floods: a Systematic Review and Meta-Analysis.

Our study systematically reviews articles about the prevalence of Post-traumatic Stress Disorder (PTSD) among children and adolescents, aiming to evaluate its prevalence after earthquakes and floods.Three databases (PubMed, Scopus, and Web of Science) were searched for articles published from 1981 to 2019 containing information on PTSD prevalence among survivors of earthquakes and floods. Articles with insufficient data on the prevalence of PTSD or without any available full-text were excluded. Major study variables consist of the prevalence of PTSD of the included studies, gender, and the elapsed time after the disaster. The overall PTSD prevalence was determined using a fixed-effect model for eligible studies. Of 4107 studies listed using our search strategy, 439 underwent full-text review, 59 records included in the systematic review, and 39 records met the criteria for meta-analysis. The pooled prevalence of PTSD among children and adolescent survivors after earthquakes and floods was 19.2% (95%CI = 18.6-19.7%), 30.0% (95%CI = 29.5-30.6%), 24.4% (95%CI = 23.4-25.4%) and 20.4% (95%CI = 19.1-21.7%), in the first, second, third and fourth six-month intervals after the disaster, respectively. Our analysis also revealed that PTSD was more prevalent among girls (p < 0.001). The absence of psychological support for affected areas considerably increases the risk of PTSD among survivors. Our results indicated that children and adolescents, especially girls, are more vulnerable and should be in top priority. The governments should refine their policies on post-disaster services and run early screening, immediate intervention, and ongoing monitoring for PTSD, as well as mental and emotional supports.

FKBP5 Genotype Linked to Combined PTSD-Depression Symptom in Chinese Earthquake Survivors.

BACKGROUND: Post-traumatic stress disorder (PTSD) and depression are common mental disorders in individuals experiencing traumatic events. To date, few studies have studied the relationship between genetic basis and phenotypic heterogeneity of traumatized individuals. The present study examined the effects of four FKBP5 SNPs (rs1360780, rs3800373, rs9296158, and rs9470080) in four postdisaster groups (low symptom, predominantly depressive, predominantly PTSD, and combined PTSD-depression symptom groups) as identified by latent profile analysis. METHODS: A total of 1,140 adults who experienced the 2008 Wenchuan earthquake participated in our study. Earthquake-related trauma, PTSD, and depressive symptoms were measured using standard psychometric instruments. The four FKBP5 SNPs were genotyped using a custom-by-design 2 × 48-Plex SNP scan™ Kit. RESULTS: After adjusting for covariates, the main and gene-environment interaction effects of rs9470080 were all significant when the combined PTSD-depression group was compared with the low symptoms, predominantly depression and predominantly PTSD groups. rs9470080 TT genotype carriers had a higher risk of developing high co-occurring PTSD and depression symptoms than the C allele carriers. However, when trauma exposure was severe, the TT genotype carriers and C allele carriers did not differ in the risk of developing high co-occurring PTSD and depressive symptoms. The other three SNPs demonstrated no significant effects. Moreover, the rs3800373-rs9296158-rs1360780-rs9470080 haplotype A-G-C-T was found significantly associated with combined PTSD-depression symptoms. CONCLUSION: Our findings support the genetic basis of phenotypic heterogeneity in people exposed to trauma. Furthermore, the results reveal the possibility that the variants of FKBP5 gene may be associated with depression-PTSD comorbidity.

Effect of seawalls on tsunami evacuation departure in the 2011 Great East Japan Earthquake.

OBJECTIVE: To quantitatively evaluate the effect of seawalls on tsunami evacuation departure. METHODS: A mixed-effect Cox proportional-hazards regression model was applied to evacuation behavioural data obtained from a probability survey of survivors of the 2011 Great East Japan Earthquake and Tsunami in Iwate and Miyagi prefectures. FINDINGS: Presence of a seawall higher than the forecast tsunami height at any given time reduces the likelihood of prompt evacuation by 30%. Findings suggest the existence of a false sense of security among residents deriving from the presence of seawalls. CONCLUSION: Prompt evacuation is a key factor affecting survival. The effect of seawalls on evacuation decisions is an important policy consideration. More work is needed in disaster preparedness education and in the way tsunami warnings are given, taking into consideration the risk of forecast error. Priority should be given to promoting prompt evacuation and educating residents as to the uncertainty of tsunami forecasting, to ensure that residents do not ignore evacuation warnings due to false impressions of the safety provided by seawalls.

Longitudinal characteristics of resilience among adolescents: A high school student cohort study to assess the psychological impact of the Great East Japan Earthquake.

AIM: Resilience, the ability to cope with disasters and significant life adversity, is an important factor to consider when studying the mental health of populations affected by a disaster. Although high school students in a community affected by a disaster should have specific characteristics of resilience, little has been reported on the issue. This study was designed to provide initial data regarding characteristics of the resilience of high school students affected by a catastrophe. METHODS: A total of 760 high school students in Natori City, which was devastated by the Great East Japan Earthquake in 2011, were profiled, and a 3-year longitudinal study was conducted with 254 students who had entered the school in 2012. Resilience was evaluated with the 10-item Connor-Davidson Resilience Scale. The Quick Inventory of Depressive Symptomatology-Japanese version, the Zung Self-Rating Anxiety Scale, and the Impact of Event Scale-Revised were also administered to assess the students' mental health. RESULTS: Among the students who entered the high school in 2012, 28.6% showed high resilience, and the proportion increased to 42.9% in 2013 and 46.6% in 2014. The Quick Inventory of Depressive Symptomatology-Japanese version and Impact of Event Scale-Revised scores decreased significantly over the 3-year study period, but there were no significant differences in the Zung Self-Rating Anxiety Scale scores over time. CONCLUSION: This initial study profiling the characteristics of resilience among adolescents suggests that resilience is a highly changeable component of mental health among people who have faced adversity. Resilience can be a useful indicator of recovery from adversity and a target of interventions for improving mental health conditions.

Victims of Fukushima Daiichi nuclear power plant accident in long-lasting disillusionment phase.

This study describes the existence of the long-lasting disillusionment phase for the victims after the accident at the Fukushima Daiichi Nuclear Power Plant following the Great East Japan Earthquake in March 2011. Through analyzing the mental situation of the victims, the situations were categorized into 2 groups for forced evacuees: "in the disillusionment phase" and "in the reconstruction phase," Other 2 groups are for host Iwaki residents: "with negative feelings against evacuees" and "leading their life constructively." The negative feeling enhances the vicious psychological cycle for the evacuees in the long-lasting disillusionment phase and repeating emotion of survivor's guilt in the reconstruction phase. We propose that people who were getting back to a normal life while leading their life constructively should raise their voices in favor of living together with evacuees.