Investigation On Occurrence Rule Of Earthquake Casualties And Survivors' Physical And Mental Trauma

BackgroundOver the past century,since the 1990 s,earthquakes have been frequently occurring worldwide and causing the highest number of casualties compared to all other natural hazards.Since 1990,330 earthquakes of different magnitudes have occurred worldwide.In total,2.58 million people were killed,2.91 million were injured,and 22.83 million people became homeless.The economic loss is estimated at USD 8,046 billion.China reports the highest number of deaths due to earthquakes.In particular,the Sichuan earthquake in 2008 and Yushu earthquake in 2010 have resulted in huge casualties.Earthquakes cause much trauma to their victims,both physical and mental.Physical trauma refers to the injuries to body tissues and organs from mechanical causes such as the collapse of buildings during earthquakes.Mental trauma refers to the mental disorders caused by the psychological impact of witnessing the misery and devastation caused by earthquakes.It mainly refers to Post-Traumatic Stress Disorder(PTSD).Rapid medical rescue is the first task in earthquake response and emergency management,while medical treatment and psychological care form the core of earthquake rescue and relief.Earthquake casualty data include the total number;time series patterns;and complex causes of casualties and types,affected areas,and causes of injuries.We need to understand the basic patterns of earthquake injuries and the typical compositions of different levels and types of injuries such that we can scientifically allocate medical resources.Meanwhile,knowledge regarding the rates of earthquake-induced PTSD and the risk factors of psychological trauma can provide the basis for psychological rescue resource deployment and psychological treatment target selection.More importantly,acute trauma due to earthquakes seriously affects the health of victims.At present,it is widely accepted that health comprises three components:(1)physical health,including illness,chronic symptoms,and self-evaluated health;(2)mental health,including anxiety,depression,cognition,joy,and contentment;and(3)social health,which is related to the size of one's social network,frequency of social interactions,and degree of social engagement.Among these three components,physical health and mental health are the most important.Therefore,the health consequences of earthquakes involve both physical injuries and psychological trauma.Researches on the physical and mental health of victims following earthquakes are significant in evaluating and improving the efficiency of medical rescue.This study firstly makes full use of empirical research data from Lushan and Ludian earthquake to anlyse injury types?locations and causes of inpatients as a result of earthquake,to analyse physical and psychological health status among earthquake survivors.Meanwhile,this study collects online data to analyse the total amount and time series characteristics of earthquake casualties and to investigate the complex causes of such casualties.Besides,worldwide earthquake injury data were integrated to facilitate the analysis of injury characteristics such as types,locations,and causes under different earthquake magnitudes and economic development levels.Finally,the prevalence rate and risk factors of post-traumatic stress disorder were studied to filter the population prone to psychological trauma.These provide new insights for improving the victims' health during reconstruction and rehabilitation.Research Areas and MethodologyThis study comprises five sections.Section 1,Introduction,provides an outline for the entire project by presenting the research background in detail;domestic and foreign research developments;and the objectives,content,methodology,and technology roadmap of this project.Section 2 includes two empirical researches on the victims' health after earthquake.Data collected through onsite investigation after Lushan earthquake were subjected to study the injury characteristics of inpatients,and psychological changes among survivors.Data collected through onsite investigation after Ludian earthquake were subjected to study health status of quake-stricken populations and impacts of earthquake trauma on their physical and mental health.Section 3 examines the occurrence rule of earthquake casualties.Global earthquake casualty time series data were analyzed by random coefficient models to understand the casualty time series patterns after earthquakes and to offer a basis for dynamic casualty assessment.Besides,quantile regression models were applied to investigate the factors affecting the number of casualties and find the key factors affecting the total number of casualties.Meanwhile,global earthquake injury data were collected to analyse types,locations,and causes of injuries under different earthquake magnitudes and economic development levels with meta.Section 4 examines the occurrence of mental disorders in earthquake victims.A meta-analysis on different literatures was conducted to calculate the rates of PTSD occurring in adults and adolescents after earthquakes and filer the risk factors leading to psychological trauma according to sociological factors,and trauma factors during and after earthquakes.Section 5 summarizes the main findings,breakthroughs,limitations,and future research directions of this study.Conclusions(1)Time series patterns,and complex causes of casualtiesIn general,the time series casualty pattern gives a logarithmic convex function.It shows a parabola,in which the values increase rapidly at first and the rate of increase slows down with time.Based on the calculations performed by forecasting models,half the total casualties are usually certified in the first 23 hours after an incident,and 80% of the total casualties are usually certified in the first 77 hours after an incident.For strong earthquakes(total number of casualties > 1000),the accumulative number of casualties reaches half the total after the 52 ed hours while only after the 231 st hours reaches 80% of the total only after the 231 st hours.This time far exceeds the Golden Hour of 72 hours.Further,this study discovered that magnitude is the most direct and primary factor affecting the scale of casualties.At higher magnitudes,the effects of other risk factors(such as the time of occurrence)will be reinforced,resulting in a large scale of casualties.Often,China experiences particularly strong earthquakes.Due to the wide expanse of stricken areas,high numbers of casualties,and a complicated geography,the preparation and operation of rescue and relief are challenging for large-scale earthquakes in the country.(2)Types,locations,and causes of injuriesAll available earthquake injury data were collected to establish a standardized global earthquake injury database.Among the various types of injuries inflicted by disasters,bone fractures are the most common and contribute to 48.37% of all injuries.Soft tissue injuries are the second most common injuries and are approximately 38.02% of the total.The proportions of infection,nerve injuries,burns,crush injuries,and amputation are smaller and are 7.84%,4.87%,0.98%,8.17%,and 2.94%,respectively.Limbs are the most commonly injured parts,and 48.61% of all the injuries involve limbs.Other commonly injured areas are,in the descending order,torso(29.91%),multiple injures to one part of the body or one organ(19.71%),head and neck(16.31%),internal organs(15.12%),chest(9.92%),spine(8.88%),and the abdomen(5.90%).Among different causes,being hit,falling,and being buried account for 53.17%,29.00%,and 25.46% of all injuries,respectively.(3)Rate of earthquake-induced PTSD,and susceptibility factorsThe average rate of PTSD in adults after an earthquake is 25.88%,while that in adolescents is 22.51%,which is significantly lower.It is noted that the rate decreases with time.Half a year after the incident,the rate in adults becomes 23.95%,whereas that in adolescents is 16.53%.The rate of PTSD in China is lower than the global average.In the country,the rate in adults is 23.97%,while that in adolescents is 18.78%.Older,female,or less educated adults are more prone to PTSD.Adults who have experienced trauma before or situations of being trapped during earthquakes are also susceptible to PTSD.Other susceptibility factors for adults include being scared or injured,witnessing casualties,the loss of family members,the lack of social support,unemployment,and economic or property loss.Among adolescents,females are more prone to PTSD.Other susceptibility factors for adolescents include being trapped during the incident,being scared or injured,witnessing casualties,the loss of family,and economic loss.(4)Empirical research on victims' physical and mental health status and related risk factors after earthquakes.Earthquakes seriously damage the physical and mental health of victims.The mean scores of the CiOP-S and CiON-S were 26.61 and 8.12,which are better than survivors' after Wenchuan earthquake.The factors associated with positive psychological changes included ethnic minority,high level of education,high household income,not injured in the earthquake,not trapped during the earthquake,and having experienced the Wenchuan earthquake.The factors associated with negative psychological changes included female gender,ethnic minority,low household income,history of diseases,injured during the earthquake,and trapped during the earthquake.At the same time,this study found that the physical and mental health of adult victims in Ludian County after an earthquake was lower than the average values for Chinese adult populations(47.41 vs.50 and 37.42 vs.50,respectively).Similar values were observed among adolescents(46.2 vs.49.8 and 36.3 vs.45.4,respectively),as well.Among adults,physical health treatment targets include the elderly,people who were trapped during the incident,those with economic or property loss,those with a medical history,and those who were not involved in rescue operations.Among adolescents,physical health treatment targets are females,ethnic minorities,those who were trapped or injured,and those with damaged homes.Both adult and adolescent targets for mental health rehabilitation include those who felt fear during the incident,experienced family losses,were involved in rescue,and were trapped.