Rates And Related Factors Of Repetition,Suicide And Death By Other Causes Following Self-harm

BackgroundSelf-harm is also referred as deliberate self-harm or self-injury.Self-harm is usually defined as intentional self-poisoning and/or self-injury regardless of motive and intention Suicide attempt and parasuicide are also included in this definition.Self-harm with suicide intent in this study is defined as suicide attempt.The definition of suicide or suicide death generally refers to the spontaneous,intentional consequences of action.The case himself fully understands or expects the fatal consequences of this action.According to the data released by World Health Organization(WHO)in 2018,suicide rate was 10.6 per 100,000 for the global population in 2016.The rate was 13.5 per 100,000 for males and 7.7 per 100,000 for females.Suicide rate in China in 2016 was 9.7 per 100,000,with a rate of 9.1 per 100,000 for males and 10.3 per 100,000 for females,indicating a distinct characteristic that the male suicide rate is lower than the female suicide rate.China,like the other parts of the world,has a high suicide rate among the elderly.In the meantime,China has a higher suicide rate in rural areas than that in cities,suggesting the need of prioritizing suicide prevention in rural area of China.There is no unified data on the rate of self-harm due to the different methods of definition and approaches of data acquisition,and the fact that many cases of self-harm cannot be recorded because they do not go to the hospital for treatment.The WHO estimates that the rate of suicide attempt(about 200 per 100,000)is about 20 times higher than suicide.The literature review of self-harm shows that the lifetime rate of self-harm in European and American populations is about 3%-5%.The WHO conducted a random sampling survey among 10 countries in 2004 and showed a rate of self-harm ranging from 0.4%to 4.2%in those countries.A large number of studies have proved that age and gender distribution are different in self-harm and suicide.Worldwide,being female is a related factor for self-harm whereas being male is a related factor for suicide.Self-harm mostly occurred in teenagers and young adult population,while suicide mostly occurred in the elderly.At the same time,self-harm and suicide also share many related factors,such as negative life events,mental disorders,genetic factors and so on.Until now,there have been two ways to get information about self-harm around the world.The first way is through medical records from the hospitals or other medical units The second way is through the epidemiological survey of self-harm.In China,there is no systematic registration to uniformly manage self-harm.Most studies on self-harm and suicide attempt are cross-sectional and case-control designs based on epidemiological surveys and have focused on adolescents.At present,there is a lack of large cohort studies focusing on self-harm,especially in mainland China.Self-harm is often recurrent,and the risk of suicide following self-harm is 30-130 times higher than that of the general population.The rate of repetition and suicide following self-harm varies greatly between gender,age and region.Geographically,compared with western countries,Asian region has a lower rate of repetition and a similar rate of suicide following self-harm.For gender,the reported rates of repetition in previous studies are inconsistent,but the reported rate of suicide following self-harm are generally higher in males than that in females.By age groups,there are also inconsistencies in the reported age-specific rate of repetition following self-harm but the reported rates of subsequent suicide increase with increasing age.Similar with the related factors for self-harm and suicide,the related factors associated with repetition and suicide following self-harm are mainly concentrated on gender,age,psychiatric disorders,physical illness and low socioeconomic status.While there is no formal evidence on how gender is related to repetition of self-harm,research has shown that the males are at an increased risk for subsequent suicide following self-harm while young people are at increased risk for repetition following self-harm.The risk of suicide following self-harm is higher in the elderly.Many factors,such as psychiatric disorders,physical illness and low socioeconomic status,do not have consistent conclusions that have been proved to be associated with repetition and suicide following self-harm.Apart from repetition and suicide following self-harm,many studies have also addressed death by other causes following self-harm.In general,the rate of death by other causes following self-harm is about 1%-2%per year,which is higher than that of suicide following self-harm.The standardized mortality ratio(SMR)of other causes following self-harm is about 4-10,which is also lower than that of suicide.The related factors of death by other causes following self-harm include male gender,being the elderly.ObjectivesIn view of existing limitations,missing knowledge in the literature and availability of data,this dissertation uses data from Norwegian national registers and from a follow-up cohort of rural suicide attempters in Shandong province and aims to investigate the rates of repetition,suicide and death by other causes following self-harm and to search significant related factors associated with these outcomes.The results of related factors in Norway,Shandong and other published studies are further summarized through a meta-analysis.The overall purpose is to make a detailed understanding of the outcome following self-harm.The specific objectives are as follows:1.To investigate the rate of repetition following self-harm,and to explore the related factors of single recurrence and frequent repeat of self-harm with data Norwegian national registers.2.To investigate the rate of suicide,death by other and all causes following suicide attempt and to explore the corresponding related factors in rural China.3.To conduct a meta-analysis on the related factors of repetition and suicide following self-harm using the combined data from Norway,rural China and other published studies.MethodsThe Norwegian part of this study used data from several Norwegian national register-based systems linked by unique personal identification numbers issued to all Norwegians at the time of birth or migration.All Norwegian residents aged above 10 years old were included to find records of self-harm.The study period was from January 1,2008 to December 31,2013.All patients of self-harm receiving emergency somatic treatment and related services in hospitals were included in this study,which was recorded in the Norwegian patient registry.Kaplan-Meier method was used to plot the survival curve and thereby obtain the cumulative rate of repetition following self-harm over the corresponding time period.Hurdle counting model combining the binary model with the zero-truncation counting model could explore the related factors of single recurrence and frequent repeat of self-harm simultaneously.This model in this study consisted of two parts.The dichotomy part analyzed the factors related to single recurrence of self-harm(repeaters and non-repeaters),and the counting part analyzed the factors related to frequent repeat of self-harm.The prospective cohort study of suicide attempt in rural China was conducted mainly by questionnaire.The questionnaire mainly included basic information,negative life events,suicide information,and diagnosis of psychiatric disorders.We used field survey and death screening to obtain the outcome data.The rates of suicide,death by other and all causes following suicide attempt were described by incidence density.Kaplan-Meier method was used to plot the survival curve and thereby obtain the cumulative rate over the corresponding time period.Cox proportional hazard regression model was used to ascertain significant related factors of death by all causes following suicide attempt.Related factors for suicide and death by other causes following suicide attempt were assessed using competitive risk models.In order to reach a consistent conclusion,we want to make use of published data from longitudinal cohort studies in the past 20 years(2000-2019)and the data in the first two part of this dissertation for a meta-analysis on the related factors of repetition and suicide following self-harm.ResultsThe study using the data from Norwegian national registers demonstrated that the cumulative rates of repetition of self-harm within 1 month,3 months,6 months,1 year,2 years,3 years and 5 years were 3.7%,6.8%,10.0%,14.0%,18.4%,21.4%and 25.0%,respectively.The number and repetition rate of self-harm in the females were higher than that in the males.The number and repetition rate of self-harm were higher in the middle-aged population(20-64 years old),while the number and repetition rate of self-harm were the lowest in elderly people(65 years old or more).The younger age,the females,comorbidity of psychiatric disorders,first-generation immigrant and single were all related to single recurrence and frequent repeat of self-harm.Self-poisoning as the only method of index self-harm,a marital status of being divorced/widowed/separated,and a median-level annual income were only associated with an increased risk of single recurrence of self-harm.In the 10-year follow-up cohort of rural China associated with suicide attempt,the incidence density of suicide following suicide attempt was 2.30(95%Cl:1.47-3.61)per thousand person-years.The incidence density of death by other causes following suicide attempt was 3.76(95%CI:2.64-5.34)per thousand person-years.The incidence density of death by all causes following suicide attempt was 6.06(95%CI:4.59-8.00)per thousand person-years.The cumulative rates of suicide at 1,2,3,5 and 10 years were 0.27%,0.63%,0.91%,1.56%and 1.83%,respectively.The cumulative rates of death by other causes at I,2,3,5,and 10 years were 0,0.09%,0.82%,1.38%,and 4.43%,respectively.The cumulative rates of death by all causes at 1,2,3,5 and 10 years were 0.27%,0.73%,1.72%,2.94%and 6.25%,respectively.The related factors of suicide following suicide attempt were elder age,history of suicide attempt and psychiatric disorders.The related factors for death by other causes included elder age and being male.The related factors for death by all causes included elder age,male gender,physical illness and psychiatric disorders.We used meta-analyses to pool the results of the first and second parts of this study with 83 longitudinal studies,and elucidate the related factors of repetition and suicide following self-harm.Female,single,divorced,separated or widowed as marital status,and unemployment were related factors of repetition of self-harm.In terms of clinical factors,the diagnosis and treatment of psychiatric disorders,physical illness,history of self-harm could significantly increase the risk of repetition of self-harm.Compared with adolescents and young adults,the elderly were the protective factors for the repetition of self-harm.Besides,the males,middle-aged and the elderly,diagnosis and treatment of psychiatric disorders,physical illness and repetition of self-harm were related factors for suicide following self-harm.Low educational level was a protective factor for suicide following self-harm.Conclusions1.The rate of repetition of self-harm is relatively high over the short term.Nearly one seventh and one quarter of self-harm had repetition of self-harm within one year and five years,respectively.The repetitive rate of female is higher than the male and the elderly is lower than other age groups.2.Suicide attempters have a higher rate of suicide in the short-term following suicide attempt,while death by other causes have a higher rate in the long-term following suicide attempt.3.Younger age,female gender,low socioeconomic status,and comorbidity of psychiatric disorders are associated with an increased risk of frequent repeat of self-harm.Besides,compared with native Norwegian,first-generation immigrant had less risk of frequent repeat of self-harm4.The related factors of single recurrence of self-harm mainly include female gender,younger age,low socioeconomic status,diagnosis and treatment of psychiatric disorders,physical illness and history of self-harm5.Significant related factors of suicide following self-harm mainly include male gender,elder age,diagnosis and treatment of psychiatric disorders,physical illness and repetition of self-harm.6.Common related factors of death by other and all causes following self-harm include male gender and elder age.Physical illness and psychiatric disorders confer important related factors for death by all causes following self-harmResearch significanceThis dissertation has systematically addressed repetition and death following self-harm,and reported both the rate and related factors of repetition,suicide and death by other causes following self-harm.Through the analyses of the follow-up data of self-harm and suicide attempts from Norwegian national registers and rural China,these individual studies have produced interesting findings that may inform effective prevention and therapeutic intervention of repetition or suicide following self-harm.The varying analytic methodologies adopted in this dissertation have also demonstrated how research evidence from various social settings can be emerged so that to provide firm knowledge in the area of self-harm and subsequent outcomes.Innovations1.This study is a cohort study using data from national registration for self-harm in Norway.This study evaluated the rate and related factors of single recurrence and frequent repeat of self-harm and found that compared with native Norwegian,first-generation immigrant had less risk of frequency repeat of self-harm,which is not reported before.2.This study is a cohort study to explore the rate and related factors of suicide,death by other and all causes after suicide attempt.This study is also a cohort study with a long follow-up time(up to 10 years or more in the longest case)in mainland China,thus obtaining many results of long-term follow-up,which had a convincing conclusion.3.This study used competing risk models to explore the rates and related factors of suicide and death by other causes following suicide attempt and obtained some results,which is not reported before.