Age-period-cohort analysis of Swiss suicide data, 1881-2000

Age, period and cohort analysis of suicide trends in Australia, 1907-2020

Background

Suicide rates have been increasing in Australia since the mid-2000s, especially for women aged ≤25 years. We conducted an age-period-cohort study to investigate these recent trends in the context of historical Australian suicide rates.

Methods

Data on annual suicides in Australia from 1907 to 2020 were extracted from the General Record of Incidence of Mortality. We modelled age-specific effects for a reference cohort, after adjustment for period effects.

Findings

We found evidence of age, cohort and period effects. For males, compared to the cohort born in 1946-1950, rates were higher for all cohorts born after this year. The period effect showed peaks in the risk of male suicide in the mid 1960s and the early 1990s, followed by a decline in risk until early 2010, after which the risk began to rise again. For females, compared to the cohort born in 1946-1950, the risk of suicide was higher for all cohorts born after this, with the highest risk for those born in 2006-2010. The period effect for females showed an elevated risk of suicide in the mid 1960s followed by a sharp decline, and an increase in risk after 2009.

Interpretation

Suicide rates in Australia have fluctuated substantially over time and appear to be related to age trends as well as period and cohort trends. Advocacy and policy making tends to focus on contemporaneous changes in suicide rates. However, this study shows that focusing only on year-on-year changes in suicide rates ignores underlying trends for specific population birth-cohorts.

Funding

None.

The long-term changing patterns of suicide mortality in China from 1987 to 2020: continuing urban-rural disparity

BACKGROUND

Over the past three decades, China has experienced significant changes in urban-rural, gender, and age-specific suicide mortality patterns. This study aimed to investigate the long-term trends in suicide mortality in China from 1987 to 2020.

METHODS

Suicide mortality data were obtained from China's National Health Commission. Joinpoint regression analysis was used to examine changes in trends and age-period-cohort modeling to estimate age, period, and cohort effects on suicide mortality from 1987 to 2020. Net drift, local drift, longitudinal age curves, and period relative risks were also calculated.

RESULTS

Crude and age-standardized suicide mortality in China showed continuing downward trends from 1987 to 2020, with a more pronounced decrease in rural areas (net drift = -7.07%, p<0.01) compared to urban areas (net drift = -3.41%, p<0.01). The decline curve of urban areas could be divided into three substages. Period and cohort effects were more prominent in rural areas. Suicide risk was highest among individuals aged 20-24 and gradually increased after age 60. Females, particularly those of childbearing age, had higher suicide risk than males, with a reversal observed after age 50. This gender reversal showed distinct patterns in urban and rural areas, with a widening gap in urban areas and a relatively stable gap in rural areas.

CONCLUSIONS

Suicide mortality in China has consistently declined over the past three decades. However, disparities in age, gender, and urban-rural settings persist, with new patterns emerging. Targeted suicide prevention programs are urgently needed for high-risk groups, including females of childbearing age and the elderly, and to address the slower decrease and reversing urban-rural gender trends.

Analysis of age, period, and birth cohort effects on suicide mortality in Brazil and the five major geographic regions

OBJECTIVE

Estimate the effects of age, period, and birth cohort on suicide mortality in Brazil by major geographic region in the overall population and by sex.

METHODS

This was a time trend ecological study. National and regional suicide mortality data from 1981 to 2020 were analyzed for the overall population and by sex. Age, period, and cohort effects were calculated with a Poisson regression model using estimable functions with the Epi package of the R statistical program, version 4.2.1.

RESULTS

There were 272,716 suicides in individuals ranging from 20 to 79 years old. In the overall population, the age model-adjusted suicide mortality rates showed an upward pattern for Brazil. The most recent cohort showed the highest associated risk, 1.67 (95%CI 1.63; 1.71), while for the reference period, it was the highest risk among all the periods.

CONCLUSIONS

Suicide mortality rates have shown an upward trend with advancing age in both men and women in the Brazilian population. However, the behavior of the period effect and cohort depends on the population analyzed and regional distribution.

The influence of the age-period-cohort effects on male suicide in Brazil from 1980 to 2019

Suicide is a complex and multi-determined phenomenon. Higher rates are observed in men and are related to multiple risk factors, including mental disorders, financial crises, unemployment, and easy access to highly lethal means of perpetration, such as firearms. We studied the effects of age, period, and cohort (APC) on total and firearm-related suicides in men in Brazil and its major regions from 1980 to 2019. Death records were extracted from the Brazilian Ministry of Health's Mortality Information System. Estimable functions were used to estimate APC models, through the Epi library of the R statistical program, version 4.2.1. During the study period, Brazil had an average rate of 10.22 deaths per 100,000 men. Among regions, rates ranged from 8.62 (Northeast) to 16.93 (South). The same profile was observed in suicides by firearms. After estimating the APC models, we observed a temporal trend of increasing total suicides for Brazil and regions, except for the South region, where the trend was stationary. The trend was downward for firearm suicides for all locations. A positive gradient was observed in the mortality rate with advancing age for total suicides; and peak incidence between 20-29 years, with subsequent stabilization, for suicides perpetrated by firearms. There was a reduction in the risk of death for suicides perpetrated by firearms in relation to the reference period (1995-1999) for all locations, except in the North region, where the effect was not significant. The younger generations from the 1960s onwards had a higher risk of death from total suicide and a lower risk for those perpetrated by firearms in relation to the reference cohort (1950-1954). We observed a reduction in the mortality trend for suicides perpetrated by firearms, a reduction in the risk of death in the 2000s and for men born after 1960. Our results suggest reducing the risk of death from suicide by firearms in Brazil and regions. However, there is an upward trend in mortality from total suicides in the study period (1980-2019) and for younger cohorts.

The Applicability of Linehan Risk Assessment Scale: a Cross-Sectional Study from Alexandria Poison Centre, Egypt, During the COVID-19 Pandemic

Background/Objective

Suicide is a critical health problem that is significantly rising during the COVID-19 pandemic worldwide, yet it is still under-reported in Egypt. To date, a deficiency of a reliable scale to probe the risk factors underlying suicide liability among patients with deliberate self-poisoning. The study’s objective was to offer a snapshot of the pattern of self- poisoning in Egypt during the COVID-19 pandemic.

Methods

Using the Linehan Risk Assessment and Management Protocol LRAMP, a psychological assessment was applied to evaluate vulnerable patients needing urgent psychiatric support and emphasize the influence of previous suicidal behaviors. A cross-sectional study was conducted on all patients admitted to Alexandria Poison Centre with deliberate self-poisoning biosocial and poisoning data that were recorded in a specially designed sheet. All patients were interviewed for underlying risk factors and protective factors for suicidal behavior.

Results

Significant relation was recorded between previous suicidal attempts and psychiatric diseases. CNS depressant drugs and rodenticides recorded the highest frequency. The calculated score (suicide and protective factors) was higher in patients with previous suicidal attempts.

Conclusion

The study was the first to test the applicability of Linehan scale in Alexandria Poison Centre. The results are promising; however, multicenter replication of the concluded findings will be valuable.

Risk-Taking Behavior among Suicide Attempters

Background: Suicidal behavior is a major mental health concern both for the individual and for the public health. Among others, suicidal behavior is associated with impulsivity, risk taking, pain tolerance, and a state of overarousal. In the present study, we investigated if suicide attempters (SAs) reported higher scores for risk-taking when compared with healthy controls (HC) of the general population. Methods: A total of 616 individuals (mean age: 27.07 years; 51.5% females) took part in the study; of those, 240 (39%) were individuals with a suicide attempt (SA) within a time lapse of one to three months, and 376 (61%) were healthy controls (HC). Participants completed a series of self-rating questionnaires covering sociodemographic information, risk-taking (Risk-Taking Questionnaire 18; RT-18), and suicidal behavior (Suicide Behaviors Questionnaire-Revised; SBQ-R). Results: Compared with HCs, individuals with SA reported higher risk-taking and suicidal behavior scores. The risk-taking questionnaire yielded a four-factor solution: Thrill and sensation seeking; Cautious procedure; Cautious decision making; Impulsive behavior. Compared with HCs, SAs showed the highest scores for thrill and sensation seeking and impulsive behavior. Conclusions: Compared with healthy controls, individuals reporting a recent suicide attempt also reported a higher propensity to thrill and sensation seeking and impulsive behavior as a proxy of risk-taking behavior. The present results corroborate the notion that, among others, suicide attempts appeared to be less related to premeditation, but rather to impulsive and thus spontaneous behavior.

Role of Foreign-Born Status on Suicide Mortality in Spain Between 2000 and 2019: An Age-Period-Cohort Analysis

Objectives: To examine recent age-period-cohort effects on suicide among foreign-born individuals, a particularly vulnerable sociodemographic group in Spain. Methods: Using 2000-2019 mortality data from Spain's National Institute of Statistics, we estimated age-period-cohort effects on suicide mortality, stratified by foreign-born status (native- vs. foreign-born) and, among the foreign-born, by Spanish citizenship status, a proxy for greater socioeconomic stability. Results: Annual suicide mortality rates were lower among foreign- than native-born individuals. There was heterogeneity in age-period-cohort effects between study groups. After 2010, suicide mortality increased markedly among the foreign-born-especially for female cohorts born around 1950, and slightly among native-born women-especially among female cohorts born after the 1960s. Among native-born men, suicide increased linearly with age and remained stable over time. Increases in suicide among the foreign-born were driven by increases among individuals without Spanish citizenship-especially among cohorts born after 1975. Conclusion: After 2010, suicide in Spain increased markedly among foreign-born individuals and slightly among native-born women, suggesting an association between the downstream effects of the 2008 economic recession and increases in suicide mortality among socioeconomically vulnerable populations.

Patterns of suicide deaths in Hungary between 1995 and 2017

Hungary has had one of the highest suicide mortality rates in the world for decades. Investigating seasonality of suicide deaths is essential as its findings could be key elements in the prevention. In our study we have analyzed the seasonal effect in suicide mortality in relation to possible risk factors in Hungary during 1995–2017.

Data on the numbers of suicide deaths were obtained from a published online database. Negative binomial regression was employed to investigate the effect of possible risk factors and seasonal and annual trends in suicide rates. The seasonal effect was further investigated, adding a significant risk factor from the “initial” negative binomial regression.

The suicide risk was significantly (p < 0.001) higher in men than in women (incidence rate ratio: 3.48), and it increased with age and decreased with education level. Marriage was a protective factor against suicide. Annual suicide mortality declined significantly (p < 0.001 for trend) from 36.7 (95% confidence interval: 35.5–37.9) to 16.5 (15.7–17.3) per 100,000 persons per year during the study period. Significant seasonality was found in suicide rates with a peak in late June. Similar peaks were observed at each level of each risk factor. There were differences in peaks by suicide method. The peak of non-violent suicides was in early June; suicides committed by violent methods peaked half a month later.

This study suggests that there was a significant seasonal effect on suicide deaths between 1995 and 2017, which remained significant even in the presence of each risk factor. To our knowledge, this has been the first study to investigate the seasonal pattern so extensively in Hungary. Our findings confirm that the environmental effects are involved in the etiology of suicide mortality.

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Significant seasonality was found in suicide rates with a peak in late June.

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Seasonal effect remained almost unchanged after adjusting sociodemographic factors.

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There were differences in seasonal peaks by suicide method.

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Environmental effects are involved in the etiology of suicide mortality.

Suicide time-series structural change analysis in Portugal (1913-2018): Impact of register bias on suicide trends

BACKGROUND

Suicide is a potentially preventable cause of death. Epidemiology might help to identify death determinants and to monitor prevention strategies. Few studies address secular trends in suicide deaths, and even fewer describe trend-changes in relation to data collection/registration bias. Moreover, suicide is admittedly underreported. It is crucial to validate results in the context of other external causes of death trends, such as unintentional and undetermined intent deaths. We aimed to explore trends in suicide and other external causes of death in Portugal from the inception of registries until 2018, considering breaks in series.

METHODS

We collected data from all available official primary sources. We calculated cause-specific age-standardized death rates (SDR) by sex for ages equal or higher than 15 years with reference to the European Standard Population. We considered suicide (S), undetermined intent deaths (UnD), accidents (Accs), and all causes of death (ttMty). A time-series structural analysis was executed.

RESULTS

Suicide and other external causes of death rates were consistently higher in males than females. A global decline of deaths by suicide, undetermined intention and unintentional is observable. Breakpoints in years 1930, 1954, 1982, 2000-2001 were associated with major changes in deaths registration procedures or methodology.

CONCLUSIONS

The epidemiology of suicide in Portugal has changed over 106 years. However, adjusted data and consideration of bias reduce trends fluctuation. Trend changes are akin to specific changes in methodology of death registry. Suicide surveillance will improve with more reliable and stable procedures.

Age, period, and cohort effects on suicide death in the United States from 1999 to 2018: moderation by sex, race, and firearm involvement

The role of sex, race, and suicide method on recent increases in suicide mortality in the United States remains unclear. Estimating the age, period, and cohort effects underlying suicide mortality trends can provide important insights for the causal hypothesis generating process. We generated updated age-period-cohort effect estimates of recent suicide mortality rates in the US, examining the putative roles of sex, race, and method for suicide, using data from all death certificates in the US between 1999 and 2018. After designating deaths as attributable to suicide according to ICD-10 underlying cause of death codes X60-X84, Y87.0, and U03, we (i) used hexagonal grids to describe rates of suicide by age, period, and cohort visually and (ii) modeled sex-, race-, and suicide method-specific age, period, and cohort effects. We found that, while suicide mortality increased in the US between 1999 and 2018 across age, sex, race, and suicide method, there was substantial heterogeneity in age and cohort effects by method, sex, and race, with a first peak of suicide risk in youth, a second peak in older ages-specific to male firearm suicide, and increased rates among younger cohorts of non-White individuals. Our findings should prompt discussion regarding age-specific clinical firearm safety interventions, drivers of minoritized populations' adverse early-life experiences, and racial differences in access to and quality of mental healthcare.

Serum oxytocin concentrations in current and recent suicide survivors are lower than in healthy controls

BACKGROUND

Suicide and suicide attempts are dramatic events both for the individuals concerned and for their social circles. From a psychopathological perspective, suicidal behavior could be understood as a severe breakdown in relations with their social worlds. Oxytocin is a neuropeptide highly involved in the perception of facets of social relationship such as their quality feelings of belongingness, and mutual trust. Given this, we expected that serum oxytocin concentrations would be lower in current and recent suicide survivors than in healthy controls.

METHODS

A total of 48 participants (mean age: 27 years; 62.5% females) took part in the study. Of these, 16 (62.5% females) survived a suicide attempt 12-24 h ago; 16 (62.5% females) had made a suicide attempt about 12 weeks ago, and 16 (62.5% females) were healthy age- and gender-matched controls. Blood samples were taken in the morning to assess serum oxytocin concentrations. Participants also completed questionnaires covering sociodemographic information and a scale assessing suicidal ideation.

RESULTS

Compared to healthy controls, suicide survivors had significantly lower serum oxytocin concentrations, but these levels did not differ between current and recent suicide survivors. Compared to healthy controls and recent suicide attempters, current suicide attempters recorded significantly higher scores on the Beck scale for suicidal ideation. Across the sample as a whole, higher scores for suicidal ideation were associated with lower serum oxytocin concentrations. Serum oxytocin concentrations and scores on the Beck scale for suicidal ideation did not differ between females and males.

CONCLUSIONS

Given that oxytocin is a neurobiological correlate of subjectively perceived quality of social interaction and social relationships, the results support the notion that suicide attempts are closely linked to suicide survivors' perceptions of the quality of their social lives. Speculatively, and based on the serum oxytocin concentrations, it also appears that 12 weeks after a suicide attempt, the survivor's perceived quality of social life has not significantly improved.

Suicide mortality in Spain (1984-2018): age-period-cohort analysis

OBJECTIVE

To assess the effects of age, period and cohort suicide mortality trend in Spain (1984-2018).

METHODS

Mortality and population data were obtained from the National Institute of Statistics. The analysis of the effect of age, period of death and birth cohort on the evolution of suicide mortality in the period 1984-2018 was performed using a web tool for age-period-cohort analysis provided by the Division of Cancer Epidemiology and Genetics of the National Cancer Institute of the USA.

RESULTS

Rates increase with age (age effect) in both sexes. The period effect shows, in males, an increase over the period 1984-1998 followed by a significant decrease until 2018. In females, rates remain stable over the period 1987-2002, decrease during 2007-2012 (p < 0.05) and eventually stabilise. In both males and females, the risk decreases in each successive birth cohort between 1904 and 1939. Subsequently, the risks increase until the birth cohort of the period 1964-1974 after which the risk decreases for males and remains stable for females.

CONCLUSION

A better understanding of the effects of the birth cohort could open new doors in suicide prevention.

Historical trends in suicide risk for the residents of mainland China: APC modeling of the archived national suicide mortality rates during 1987-2012

PURPOSE

Distinctive and dramatic changes in the history of China with a rapid suicide decline in recent years present an opportunity to investigate the risk of suicide. In this study, we investigated suicide risk with a historical perspective with archived data to inform suicide research and prevention policies and strategies.

METHOD

Documented age-specific suicide mortality rates in 1987-2012 were decomposed into age, period, and cohort effect using APC-modeling method and intrinsic estimator (IE) technique. The estimated effects were further analyzed by numerical differentiation.

RESULTS

The data satisfactorily fit the constructed APC models. Cohort effect indicated that suicide risk in China fluctuated at very high levels during 1903-1967, followed by a sharp decline during 1968-1977, and reached the lowest level in 1983-1987 before increased again. Period effect confirmed the declining trend since 1987. Three sunny cohorts with reduced suicide risk and four cloudy cohorts with increased risk were, respectively, associated with significant cultural, social, political, and economic events in China since the 1900s.

CONCLUSIONS

The mega trends in the suicide risk at the population level are closely related to significant historical events in China. Suicide is anticipated to increase because of the growing risk for the young cohorts (particularly young females) as the country further develops. Study findings suggest the significance of national strategies for suicide prevention and control, including maintenance of social harmony and stability, provision of more opportunities for development, enhancement of social integration, and restriction of suicide facilitating factors.

Female Gender, Marital and Family Problems, and Feelings of Guilt Are Related to Self-Immolation Suicide Attempts

BACKGROUND

Self-immolation (SI) is considered one of the most painful, dramatic, and at the same time most inexplicable methods of suicide, with a high social impact. Prevalence rates are particularly high in Iran, and in north-western Iran specifically. Here, we report sociodemographic, psychological, and psychiatric characteristics of patients attempting self-immolation (PSIs), compared to patients with accident burns (PABs).

METHOD

Patients referred to the Burns Emergency Unit of the Besat Hospital (Hamadan, Iran) were enrolled in the present study between winter 2015 and summer 2016. After burn-related treatments and surgery, a thorough interview was undertaken covering sociodemographic characteristics, burn-related information, and psychiatric background.

RESULTS

A total of 79 patients were enrolled. Among these, 19 (31.7%) had attempted suicide via SI. Compared to the PABs, the PSIs were predominantly females; they reported family and marital problems as the main triggers for SI. The psychiatric interviews indicated that PSIs often suffered from major depressive disorders, adjustment disorders, and bipolar disorders. The prevailing feelings reported were guilt and shame. A binary logistic regression showed that feelings of guilt and marital and family problems predicted SI.

CONCLUSIONS

The prevalence of SI was surprisingly high. Marital and family conflicts as a proxy for highly distressing social interactions, along with female gender and feelings of guilt and shame were strongly associated with SI. Family and couple counseling specifically tailored to difficulties experienced by women might reduce the risk of SI.

Cholecystokinin (CCK) level is higher among first time suicide attempters than healthy controls, but is not associated with higher depression scores

Suicide and suicide attempts are dramatic events for both the individuals concerned and for their social environments. Efforts have been made to identify reliable biological predictors of suicide and suicide attempts. In the present study, we focused on one potential marker, cholecystokinin (CCK), among first time suicide attempters. A total of 25 suicide attempters (mean age: 30 years; 80% females) and 23 healthy controls were enrolled in the present cross-sectional study. Experts rated participants' symptoms of depression (Hamilton Depression Rating Scale; HDRS). Blood levels of CCK levels were assessed. Suicide attempters had CCK levels 22.67 times higher and HDRS scores 14.33 higher than healthy controls. CCK levels were only weakly associated with HDRS scores. CCK appears to be a fairly reliable biomarker for suicide attempts. However, CCK levels were not associated with depression scores, making it difficult to match biological markers to depressive behaviour.

Age, Period, and Cohort Effects on Suicide Mortality in South Korea, 1992⁻2015

Although the effects of age, period, and cohort (APC) on suicide are important, previous work in this area may have been invalid because of an identification problem. We analyzed these effects under three different scenarios to identify vulnerable groups and thus overcame the identification problem. We extracted the annual numbers of suicides from the National Death Register of Korea (1992⁻2015) and estimated the APC effects. The annual average suicide rates in 1992⁻2015 were 31.5 and 14.7 per 100,000 males and females, respectively. The APC effects on suicide were similar in both sexes. The age effect was clearly higher in older subjects, in contrast to the minimal changes apparent during earlier adulthood. The birth cohort effect showed an inverted U shape; a higher cohort effect was evident in females born in the early 1980s when period drift was larger than 3.7%/year. Period effect increased sharply during the early 1990s and 2000s. We found that elderly and young females may be at a particularly high risk of suicide in Korea.

Temporal distribution of suicide mortality: A systematic review

BACKGROUND

suicide is a problem with world impact and the leading cause of premature deaths. The study of its distribution over time can bring a changed understanding of parameters attributed to, and the prevention of, suicide.

AIM

to identify the temporal pattern of suicide by systematic review.

METHODS

Pubmed (Medline), LILACS, Virtual Health Library (VHL), Science Direct and Scopus (Elsevier), Web of Science (Thomson Reuters) and PsyNET (APA) were searched, using suicide-related descriptors and terms, for observational epidemiological studies of the temporal distribution of suicide. The review protocol was registered in PROSPERO (CRD42016038470).

LIMITATIONS

The lack of uniformity in reporting or standardisation of methodology in the studies selected, hindered comparison of populations with similar socioeconomic and cultural profiles, considerably limiting the scope of the results of this review.

RESULTS

forty-five studies from 26 different countries were included in this review. Clear seasonal patterns were observed by day of the week, month, season and age-period-cohort effects. Few studies studied by trend, time of day or day of the month.

CONCLUSION

the review findings provide further evidence of substantial temporal patterns influenced by geographic, climatic and social conditions.

Age, period and cohort effects on suicide mortality in Russia, 1956-2005

Background

Russian suicide mortality rates changed rapidly over the second half of the twentieth century. This study attempts to differentiate between underlying period and cohort effects in relation to the changes in suicide mortality in Russia between 1956 and 2005.

Methods

Sex- and age-specific suicide mortality data were analyzed using an age-period-cohort (APC) approach. Descriptive analyses and APC modeling with log-linear Poisson regression were performed.

Results

Strong period effects were observed for the years during and after Gorbachev’s political reforms (including the anti-alcohol campaign) and for those following the break-up of the Soviet Union. After mutual adjustment, the cohort- and period-specific relative risk estimates for suicide revealed differing underlying processes. While the estimated period effects had an overall positive trend, cohort-specific developments indicated a positive trend for the male cohorts born between 1891 and 1931 and for the female cohorts born between 1891 and 1911, but a negative trend for subsequent cohorts.

Conclusions

Our results indicate that the specific life experiences of cohorts may be important for variations in suicide mortality across time, in addition to more immediate effects of changes in the social environment.

Temporal Trends of Suicide Mortality in Mainland China: Results from the Age-Period-Cohort Framework

The aim of this study is to explore the long-term trends of suicide mortality in China. We implemented the age-period-cohort (APC) framework, using data from the Global Burden of Disease Study 2013. Our results showed that the net drift of suicide mortality was -4.727% (95% CI: -4.821% to -4.634%) per year for men and -6.633% (95% CI: -6.751% to -6.515%) per year for women, and the local drift values were below 0 in all age groups (p < 0.01 for all) for both sexes during the period of 1994-2013. Longitudinal age curves indicated that, in the same birth cohort, suicide death risk increased rapidly to peak at the life stage of 20-24 years old and 15-24 years old for men and women, respectively, and then showed a decelerated decline, followed by a rise thereafter after 54 years old for men and a slight one after 69 years old for women. The estimated period and cohort RRs were found to show similar monotonic downward patterns (significantly with p < 0.01 for all) for both sexes, with more quickly decreasing for women than for men during the whole period. The decreasing trend of suicide was likely to be related to the economic rapid growth, improvements in health care, enhancement on the level of education, and increasing awareness of suicide among the public in China. In addition, fast urbanization and the effective control of pesticides and rodenticides might be the special reasons behind these trends we observed in this study.

Testing Persistence of Cohort Effects in the Epidemiology of Suicide: an Age-Period-Cohort Hysteresis Model

Birth cohort effects in suicide rates are well established, but to date there is no methodological approach or framework to test the temporal stability of these effects. We use the APC-Detrended (APCD) model to robustly estimate intensity of cohort effects identifying non-linear trends (or 'detrended' fluctuations) in suicide rates. The new APC-Hysteresis (APCH) model tests temporal stability of cohort effects. Analysing suicide rates in 25 WHO countries (periods 1970-74 to 2005-09; ages 20-24 to 70-79) with the APCD method, we find that country-specific birth cohort membership plays an important role in suicide rates. Among 25 countries, we detect 12 nations that show deep contrasts among cohort-specific suicide rates including Italy, Australia and the United States. The APCH method shows that cohort fluctuations are not stable across the life course but decline in Spain, France and Australia, whereas they remain stable in Italy, the United Kingdom and the Netherlands. We discuss the Spanish case with elevated suicide mortality of cohorts born 1965-1975 which declines with age, and the opposite case of the United States, where the identified cohort effects of those born around 1960 increase smoothly, but statistically significant across the life course.

Age-period-cohort analysis of suicide mortality by gender among white and black Americans, 1983-2012

Background

Previous studies suggested that the racial differences in U.S. suicide rates are decreasing, particularly for African Americans, but the cause behind the temporal variations has yet to be determined. This study aims to investigate the long-term trends in suicide mortality in the U.S. between 1983 and 2012 and to examine age-, period-, and cohort-specific effects by gender and race.

Method

Suicide mortality data were collected from the Web-based Injury Statistics Query and Reporting System (WISQARS) and analyzed with the Joinpoint regression and age-period-cohort (APC) analysis.

Results

We found that although age-standardized rate of suicide in white males, white females, black males, and black females all changed at different degrees, the overall situation almost has not changed since these changes offset each other. By APC analysis, while the age effect on suicide demonstrate an obvious difference between white males and females (with the peak at 75 to 79 for white males and 45 to 54 for white females), young black people are predominantly susceptible to suicide (risk peaks in early 20s for black males and late 20s for black females). Cohort effects all showed a descending trend, except that in white males and females which showed an obvious increase peaked in around cohort 1960. There was a similar period effect trend between different genders in the same race group, but between the races, differences were found in the period before 1990 and after 2000.

Conclusion

We confirmed that the distinction in age-specific suicide rate patterns does exist by gender and by race after controlling for period and cohort effects, which suggested that minorities’ age patterns of suicide may have been masked up by the white people in the whole population. The differences of period effects and cohort effects between white and black Americans were likely to be mainly explained by the difference in race susceptibility to economic depression.

Attitudes of midwives and maternal child health nurses towards suicide: A cross-sectional study

Perinatal women are at risk of depression and/or suicidality. Suicide is the highest cause of indirect maternal deaths in the perinatal period. Midwives and maternal child health nurses (MCHN), as key clinicians, need to be able to detect these mental health issues. Little is known about these clinicians' attitudes to suicide. In this paper, we report on the results of a cross-sectional study of midwives' and MCHN attitudes to suicide. A convenience sample of midwives (n = 95) and MCHN (n = 86) from south-eastern Victoria, Australia, was recruited into the study. Participants completed the Attitudes to Suicide Prevention Scale. The results showed that MCHN have more positive attitudes towards suicide prevention than midwives, and younger participants have more positive attitudes to suicide prevention compared to older participants. Midwives and MCHN could benefit from continuing professional education to build their knowledge and skills in assessing suicide risk for childbearing women and their families, increasing positive attitudes, improving detection, and mental health referrals.

Use of age-period-cohort models to estimate effects of vehicle age, year of crash and year of vehicle manufacture on driver injury and fatality rates in single vehicle crashes in New South Wales, 2003-2010

A novel application of age-period-cohort methods are used to explain changes in vehicle based crash rates in New South Wales, Australia over the period 2003-2010. Models are developed using vehicle age, crash period and vehicle cohort to explain changes in the rate of single vehicle driver fatalities and injuries in vehicles less than 13 years of age. Large declines in risk are associated with vehicle cohorts built after about 1996. The decline in risk appears to have accelerated to 12 percent per vehicle cohort year for cohorts since 2004. Within each cohort, the risk of crashing appears to be a minimum at two years of age and increases as the vehicle ages beyond this. Period effects (i.e., other road safety measures) between 2003 and 2010 appear to have contributed to declines of up to about two percent per annum to the driver-fatality single vehicle crash rate, and possibly only negligible improvements to the driver-injury single vehicle crash rate. Vehicle improvements appear to have been responsible for a decline in per-vehicle crash risk of at least three percent per calendar year for both severity levels over the same period. Given the decline in risk associated with more recent vehicle cohorts and the dynamics of fleet turnover, continued declines in per-vehicle crash risk over coming years are almost certain.

The historical development of suicide mortality in Russia, 1870-2007

Russia has one of the highest suicide mortality rates in the world. This study investigates the development of Russian suicide mortality over a longer time period in order to provide a context within which the contemporary high level might be better understood. Annual sex- and age-specific suicide-mortality data for Russia for the period 1870-2007 were studied, where available. Russian suicide mortality increased 11-fold over the period. Trends in male and female suicide developed similarly, although male suicide rates were consistently much higher. From the 1990s suicide has increased in a relative sense among the young (15-34), while the high suicide mortality among middle-aged males has reduced. Changes in Russian suicide mortality over the study period may be attributable to modernization processes.

Suicide in Sri Lanka 1975-2012: age, period and cohort analysis of police and hospital data

Background

Sri Lanka has experienced major changes in its suicide rates since the 1970s, and in 1995 it had one of the highest rates in the world. Subsequent reductions in Sri Lanka’s suicide rates have been attributed to the introduction of restrictions on the availability of highly toxic pesticides. We investigate these changes in suicide rates in relation to age, gender, method specific trends and birth-cohort and period effects, with the aim of informing preventative strategies.

Methods

Secular trends of suicide in relation to age, sex, method, birth-cohort and period effects were investigated graphically using police data (1975–2012). Poisoning case-fatality was investigated using national hospital admission data (2004–2010).

Results

There were marked changes to the age-, gender- and method-specific incidence of suicide over the study period. Year on year declines in rates began in 17–25 year olds in the early 1980s. Reduction in older age groups followed and falls in all age groups occurred after all class I (the most toxic) pesticides were banned. Distinct changes in the age/gender pattern of suicide are observed: in the 1980s suicide rates were highest in 21–35 year old men; by the 2000s, this pattern had reversed with a stepwise increase in male rates with increasing age. Throughout the study period female rates were highest in 17–25 year olds. There has been a rise in suicide by hanging, though this rise is relatively small in relation to the marked decline in self-poisoning deaths. The patterns of suicides are more consistent with a period rather than birth-cohort effect.

Conclusions

The epidemiology of suicide in Sri Lanka has changed noticeably in the last 30 years. The introduction of pesticide regulations in Sri Lanka coincides with a reduction in suicide rates, with evidence of limited method substitution.

Electronic supplementary material

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The role of under-employment and unemployment in recent birth cohort effects in Australian suicide

High suicide rates evident in Australian young adults during an epidemic period in the 1990s appear to have been sustained in older age-groups in the subsequent decade. This period also coincides with changes in employment patterns in Australia. This study investigates age, period, and birth cohort effects in Australian suicide over the 20th century, with particular reference to the period subsequent to the 1990s youth suicide epidemic in young males. Period- and cohort-specific trends in suicide were examined for 1907-2010 based on descriptive analysis of age-specific suicide rates and a series of age-period-cohort (APC) models using Poisson regression. Under-employment rates (those employed part-time seeking additional hours of work) and unemployment rates (those currently seeking employment) for the latter part of this time series (1978-2010) were also examined and compared with period- and cohort-specific trends in suicide. A significant increasing birth cohort effect in male suicide rates was evident in birth cohorts born after 1970-74, after adjusting for the effects age and period. An increasing birth cohort effect was also evident in female suicide rates, but was of a lesser magnitude. Increases in male cohort-specific suicide rates were significantly correlated with increases in cohort-specific under-employment and unemployment rates. Birth cohorts that experienced the peak of the suicide epidemic during the 1990s have continued to have higher suicide rates than cohorts born in earlier epochs. This increase coincides with changes to a labour force characterised by greater 'flexibility' and 'casualised' employment, especially in younger aged cohorts.

Effects of media reports and the subsequent voluntary withdrawal from sale of suicide-related products on the suicide rate in Japan

Media reports of suicides have an impact on suicide rates. However, countermeasures to this media effect have not been evaluated. We examined the association between media reports of suicides accomplished with the use of hydrogen sulfide, the voluntary stoppage of sales of suicide-related products, and suicide rates for people in their 20s, 30s, and 40s in Japan. The Box-Jenkins transfer function model was applied to monthly time series data from February 2003 to December 2009 (83 months). In the male suicide time series, media reports of suicide were not related to suicide counts (ω((R)) = 8.988, P = 0.694). Similarly, stopping the sale of bath salts was not related to the number of suicides (ω((S)) = -7.344, P = 0.694). However, in the female suicide time series, media reports of suicide were related to the number of suicides (ω((R)) = 17.225, P = 0.049). Similarly, stopping the sale of bath salts was related to the number of suicides (ω((S)) = -18.545, P = 0.040). The results suggest that stopping the sale of bath salts might be effective in reducing the number of copycat suicides among the women in their 20s, 30s, and 40s. In practice, stopping the sale of suicide-related products might be a potentially effective countermeasure to prevent copycat suicides triggered by media coverage of suicides.

Suicide in the world

INTRODUCTION

Over the past 20 years the WHO has considerably improved world mortality data. There are still shortcomings but more countries now report data and world-wide estimates are regularly made.

METHODS

Data about mortality have been retrieved from the WHO world database. Worldwide injury mortality estimates for 2008 as well as trends of the suicide rate from 1950 to 2009 were analysed.

RESULTS

Suicides in the world amount to 782 thousand in 2008 according to the WHO estimate, which is 1.4% of total mortality and 15% of injury mortality. The suicide rate for the world as a whole is estimated at 11.6 per 100,000 inhabitants. The male-female rate ratio of suicide is estimated to be highest in the European Region (4.0) and the lowest in the Eastern Mediterranean region (1.1). Among males the highest suicide rate in the 15-29 age group is in the SE Asian region, in the 45-59 age group in European males and for ages above 60 in the Western Pacific region. Females from SE Asia have a remarkably high suicide rate among 15-29-year-olds and from age 45 in the Western Pacific region. The leading country is currently Lithuania, with a suicide rate of 34.1 per 100,000 inhabitants. Also among males the suicide rate is the highest in Lithuania at 61.2. Among females South Korea with 22.1 is at the top of world suicide rates.

CONCLUSIONS

During the past six decades, according to the WHO Japan, Hungary, and Lithuania have topped the list of world countries by suicide rate, but if the current trends continue South Korea will overtake all others in a few years. The heart of the problem of suicide mortality has shifted from Western Europe to Eastern Europe and now seems to be shifting to Asia. China and India are the biggest contributors to the absolute number of suicides in the world.

Birth cohort effects in neurological diseases: amyotrophic lateral sclerosis, Parkinson's disease and multiple sclerosis

BACKGROUND

Generational differences in disease rates are the main subject of age-period-cohort (APC) analysis, which is mostly applied in cancer and suicide research. This study applied APC analysis to selected neurological diseases: amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD) and multiple sclerosis (MS).

METHODS

The analyses were based on Swiss mortality data. Age-stratified data has been available for MS, PD and ALS since 1901, 1921, and 1942, respectively. APC analysis was performed within the framework of logit models. Main effect models were extended by implementing nested effects, i.e. age effects nested in subperiods, in order to account for the fact that age profiles may change for reasons other than generational influences.

RESULTS

In preliminary analyses, APC analysis yielded noteworthy birth cohort effects in all three diseases. After implementing nested effects, the birth cohort effects disappeared in ALS, and smoothed out in PD, where they were greater for the generations born before the 1920s. In MS, the birth cohort effects remained stable, and exhibited a peak in cohorts born in the 1910s and 1920s.

CONCLUSIONS

APC analysis yielded some evidence for birth cohort effects, i.e. predisposing risk factors that may change in historical terms, in MS and PD, but probably not in ALS.

Suicide rates: age-associated trends and their correlates

BACKGROUND

Suicide rates traditionally increased with ageing. There is a paucity of studies examining factors associated with age-associated trends in suicide rates.

METHODS

The relationship between suicide rates and ageing was examined by ascertaining suicide rates in the seven age-bands 16-24 years to 75+ years from the World Health Organisation for 97 countries. The relationship between socio-economic status, income inequality, health-care expenditure, child mortality rates and life expectancy and countries with an increase, a decline and no change in suicide rates with ageing was examined using data from the United Nations.

RESULTS

In males and females there was a decline in 5 and 10 countries, an increase in 33 and 37 countries and no change in 59 and 50 countries respectively in suicide rates with ageing. Age-associated trends in suicide rates were significantly associated with socio-economic status (males) or income inequality (females), per capita expenditure in healthcare, the proportion of gross-national domestic product spent on healthcare, child mortality rates and life expectancy.

CONCLUSIONS

The current study, of factors associated with age-associated trends in suicide rates, confirmed a previously developed five sequential stage model to explain the relationship between elderly suicide rates and socio-economic status and income inequality, quality and quantity of healthcare services, child mortality rates and life expectancy.

Gender Differences in Age, Period, and Birth-Cohort Effects on the Suicide Mortality Rate in Japan, 1985-2006

Because suicide is increasingly becoming a public health threat in Japan, it is necessary to identify high-risk groups to develop effective preventive measures. The suicide mortality trends from 1985 to 2006 for Japanese aged between 15 and 79 years were analyzed by a Bayesian age–period–cohort analysis to evaluate the independent effects of age, period, and birth cohort. Age-specific effect showed an overall increase with age in both genders, but a distinct increase was noted only among men aged between 50 and 64 years. The period effect exhibited a sudden rise in 1998; this effect was more apparent in men than in women. The cohort-specific effect increased in male birth cohorts born after 1926 and in female birth cohorts born after 1956. In conclusion, a gender difference was detected in the effects of age, period, and cohort on suicide risk among Japanese.

Genetic and epigenetic analysis of SSAT gene dysregulation in suicidal behavior

It has recently been proposed that the SSAT gene plays a role in the predisposition to suicidal behavior. SSAT expression was found to be down-regulated in the brain of suicide completers. In addition, a single nucleotide polymorphism (SNP) rs6526342 was associated both with variation in SSAT expression and with suicidal behavior. In this study, we aimed to characterize the relationship between SSAT dysregulation and suicide behavior. To this end, we measured SSAT expression levels in the ventral prefrontal cortex (VPFC) of suicide completers (n = 20) and controls (n = 20) and found them to be significantly down-regulated in suicide victims (P = 0.007). To identify the basis of the regulation of SSAT expression, we performed an association analysis of 309 SNPs with SSAT transcript levels in 53 lymphoblastoid cell lines from the CEPH collection. We then examined the methylation status of the SSAT promoter region in males and females suicide completers and control subjects whose SSAT brain expression had been measured. We found no evidence to support a role for SNPs in controlling the level of SSAT expression. SSAT promoter methylation levels were not different between suicide completers and controls and did not correlate with SSAT expression levels. In addition, we found no indication of a genetic association between suicidal behavior and SNPs located within the SSAT gene. Our study provides new results which show that dysregulation of SSAT expression does play a role in suicide behavior. However, our data do not support any association between rs6526342 and variation in SSAT expression or suicidal behavior.

Suicide and suicidal behavior

Suicidal behavior is a leading cause of injury and death worldwide. Information about the epidemiology of such behavior is important for policy-making and prevention. The authors reviewed government data on suicide and suicidal behavior and conducted a systematic review of studies on the epidemiology of suicide published from 1997 to 2007. The authors' aims were to examine the prevalence of, trends in, and risk and protective factors for suicidal behavior in the United States and cross-nationally. The data revealed significant cross-national variability in the prevalence of suicidal behavior but consistency in age of onset, transition probabilities, and key risk factors. Suicide is more prevalent among men, whereas nonfatal suicidal behaviors are more prevalent among women and persons who are young, are unmarried, or have a psychiatric disorder. Despite an increase in the treatment of suicidal persons over the past decade, incidence rates of suicidal behavior have remained largely unchanged. Most epidemiologic research on suicidal behavior has focused on patterns and correlates of prevalence. The next generation of studies must examine synergistic effects among modifiable risk and protective factors. New studies must incorporate recent advances in survey methods and clinical assessment. Results should be used in ongoing efforts to decrease the significant loss of life caused by suicidal behavior.

The relationship between suicide rates and age: an analysis of multinational data from the World Health Organization

BACKGROUND

Suicide rates generally increase with age. With the emergence of studies from several countries without an increase in suicides rates with aging, a cross-national study examining the relationship between suicide rates and age was undertaken.

METHODS

The relationship between suicide rates and age was examined by ascertaining suicide rates in both sexes in seven age-bands 16-24 years, 25-34 years, 35-44 years, 45-54 years, 55-64 years, 65-74 years and 75+ years, from the World Health Organization website for all the listed countries (N = 62).

RESULTS

The main findings were: (i) there was a significant increase in suicide rates with increasing age in males and females in 25 and 27 countries respectively; (ii) there was no significant increase in suicide rates with increasing age in males and females in 31 and 29 countries respectively; (iii) suicide rates were the highest in the younger age-bands in countries without a significant increase in male suicides rates with increasing age; (iv) countries without a significant increase in the suicide rate with increasing age in both sexes, females only and males only demonstrated regional clustering; and, (v) in a small number of countries suicide rates declined with increasing age.

CONCLUSIONS

Potential explanations for regional and cross-national variations in the relationship between suicide rates and age require further study.

Age-period-cohort models for the Lexis diagram

Analysis of rates from disease registers are often reported inadequately because of too coarse tabulation of data and because of confusion about the mechanics of the age-period-cohort model used for analysis. Rates should be considered as observations in a Lexis diagram, and tabulation a necessary reduction of data, which should be as small as possible, and age, period and cohort should be treated as continuous variables. Reporting should include the absolute level of the rates as part of the age-effects. This paper gives a guide to analysis of rates from a Lexis diagram by the age-period-cohort model. Three aspects are considered separately: (1) tabulation of cases and person-years; (2) modelling of age, period and cohort effects; and (3) parametrization and reporting of the estimated effects. It is argued that most of the confusion in the literature comes from failure to make a clear distinction between these three aspects. A set of recommendations for the practitioner is given and a package for R that implements the recommendations is introduced.