High temperatures trigger suicide mortality in Brussels, Belgium: A case-crossover study (2002-2011)

Establishing and mapping heat-sensitive disease spectrum in eastern China: A comprehensive analysis of 1.4 million deaths involving 14 major disease categories

BACKGROUND

Although high temperatures can affect multiple systems and organs, the comprehensive assessment of heat-sensitive diseases remains unclear. We aimed to establish the heat-related sensitive disease spectrum and assess the relative importance of affected diseases from the health risk and burden perspectives.

METHODS

A space-time-stratified case-crossover analysis was used to examine the short-term association between high temperatures and cause-specific deaths in Jiangsu Province, China during the warm season of 2016 to 2019. A total of 14 major disease categories and 29 specific diseases were tested to identify heat-sensitive diseases. A multi-level comparison of heat-affected diseases was conducted based on the health risk and burden indicators including mortality risk, years of life lost (YLL) to measure disease burden, and value of YLL (VYLL) to measure economic burden.

RESULTS

High temperatures were associated with an increased risk of mortality from 23 specific diseases involving 12 major disease categories, including well-studied cardiovascular, respiratory, endocrine, and nervous diseases, and less-studied skin, urinary system diseases, mental and behavioral disorders, external causes, injury and poisoning, symptoms, signs and abnormal clinical, and neoplasms. The top three greatest heat-related risks of mortality from major disease categories were skin system (OR: 1.72, 95 % CI: 1.37-2.36), external causes of mortality (OR: 1.71, 95 % CI: 1.57-1.87), and nervous system (OR: 1.46, 95 % CI: 1.26-1.68), and cause-specific diseases were asthma (OR: 2.26, 95 % CI: 1.46-3.50), accidental drowning (OR: 1.85, 95 % CI: 1.42-2.40), and acute respiratory infections (OR: 1.80, 95 % CI: 1.02-3.16). In terms of both disease and economic burdens attributable to heat, cardiovascular diseases contributed to the greatest proportion, followed by neoplasms, external causes, and respiratory diseases. Within specific diseases, cerebrovascular diseases contributed the greatest disease and economic burdens, followed by ischemic heart disease, lung (neoplasm), and COPD. Furthermore, the largest heat-related reduction in life expectancy reached 5.27 years for external causes and 12.96 years for accidental drowning.

CONCLUSION

This study provides a heat-sensitive disease spectrum and resulting death risk and burden vary by different systems and specific diseases. Our findings may have implications for implementing heat-health action plans to mitigate the adverse effects of heat-sensitive diseases.

The mediating role of thyroid hormone in the association between heatwave exposure and depression severity

High-temperature exposure has been reported to be associated with depression scores and the risk of hospital visits. However, how heatwaves affect depression severity and the underlying mechanisms remains unclear. Inpatients with depression from the Anhui Mental Health Center in China between January 2020 and December 2023 were included in this retrospective study. The patients were grouped into mild, moderate and severe depression categories according to discharge diagnoses. The effects of heatwaves in two weeks prior to admission on depression severity were assessed based on mixed-effect logistic regression model, and the roles of thyroid hormones were quantified by piecewise structural equation modeling. Stratified analyses were conducted by gender, age, BMI and the COVID-19 pandemic. A total of 5,978 inpatients with depression were hospitalized 7,118 times during the study period. The depression severity escalated with the threshold and duration of heatwaves. The risk of more severe depression during heatwave exposure (≥95th percentile, ≥3 days) was 12.4 % (95 % CI: 6.1 %, 19 %) higher compared to non-heatwave conditions. The proportions of mediating effects of thyroid hormones (T3, FT3, T4 and the FT4/FT3 ratio) were 7.7 % (95 % CI: 0.3 %, 20.1 %), 13.6 % (95 % CI: 1.5 %, 30.6 %), 12.8 % (95 % CI: 4.3 %, 25.7 %) and 23.3 % (95 % CI: 11.4 %, 54.1 %) in the influences of heatwaves on depression severity, respectively. Males, young and middle-aged patients, overweight patients, and those hospitalized during the COVID-19 pandemic, were all more sensitive to heatwaves. Our study showed that heatwaves significantly correlated with depression severity. Thyroid hormones may played potential mediating roles in this association.

Empty bottles, rising risks: A case-crossover study on psychotherapeutic medication depletion and suicide triggers

OBJECTIVE

The use of psychotherapeutic medications can reduce the risk of suicide among people with mental health disorders, but little is known about the impact of exhausting these medications. This study analyzes the temporal relationship between running out of psychotherapeutic medications and suicide using a case-crossover study design.

METHODS

Pharmacy and medical claims data from the Arkansas All-Payers Claims Database were linked to death certificates to identify decedents of suicide from 2013 through 2021. Psychotherapeutic medications were categorized using a National Drug Code (NDC) ontology from First DataBank®. The dispensed date and days' supply from pharmacy claims estimated when a decedent would exhaust any prescribed psychotherapeutic. A dichotomous variable indicated if a decedent exhausted at least one psychotherapeutic during the hazard window - the seven days leading up to and including the date of death. This exposure was compared to 11 control windows - the 11 weeks immediately preceding the hazard window. Conditional logistic regression analysis estimated the odds of exhausting at least one medication during the hazard window relative to the control windows.

RESULTS

Among 853 decedents who received 4375 psychotherapeutic prescriptions, 17.0 % exhausted at least one psychotherapeutic in the hazard window, the highest among all study windows. There was a 46 % increase in the odds of exhausting at least one psychotherapeutic during the hazard window compared to the control windows (AOR: 1.46; p = 0.0001).

CONCLUSION

There is a temporal relationship between exhausting at least one psychotherapeutic medication and suicide, highlighting the need for close monitoring of medication supply for patients treated with psychotherapeutics.

Association of short-term exposure to ambient air pollution and temperature with bronchiectasis mortality: a nationwide time-stratified case-crossover study

BACKGROUND

Ambient pollution and non-optimal temperature are major risk factors for respiratory health. However, the relationships between short-term exposure to these factors and bronchiectasis mortality remain unknown.

METHODS

A nationwide, time-stratified case-crossover study across Mainland China was conducted from 2013 to 2019. Records of bronchiectasis deaths were extracted from the National Death Registration Reporting Information System. Daily concentrations of fine particulate matter (PM2.5), coarse particulate matter (PM2.5-10), nitrogen dioxide (NO2), ozone (O3), and daily temperature were obtained from high-resolution prediction models. We utilized conditional logistic regression model and distributed lag nonlinear model to explore the associations of these exposures with bronchiectasis mortality.

FINDINGS

We included a total of 19,320 bronchiectasis deaths. Air pollutant was associated with bronchiectasis mortality within the first 3 days after exposure and the exposure-response relationships were almost linear. An interquartile range increase in PM2.5, PM2.5-10, and O3 was associated with increments of 3.18%, 4.14%, and 4.36% in bronchiectasis mortality at lag 02 d, respectively. Additionally, lower temperature was associated with higher odds of bronchiectasis mortality. Compared to referent temperature (23.6 °C), the odds ratio for bronchiectasis mortality associated with extremely low temperature (P1: -13.4 °C) was 1.54 (95% CI: 1.05, 2.25).

INTERPRETATION

This national study provides compelling evidence, and highlights the necessity and importance of reducing air pollution exposures and keeping warm for susceptible populations.

FUNDING

National Natural Science Foundation of China (81925001; 82330070); Innovation Program of Shanghai Municipal Education Commission (202101070007-E00097); Program of Shanghai Municipal Science and Technology Commission (21DZ2201800); Program of Shanghai Shenkang Development Center (SHDC12023110); and Major Project of National Health Commission of China.

Associations of heat with diseases and specific symptoms in Flanders, Belgium: An 8-year retrospective study of general practitioner registration data

INTRODUCTION

Global temperature rise has become a major health concern. Most previous studies on the impact of heat on morbidity have used hospital data.

OBJECTIVE

This study aimed to quantify the association between ambient temperature and a variety of potentially heat-related medical conditions and symptoms using general practitioner (GP) data, in Flanders, Belgium.

METHODS

We used eight years (2012-2019) of aggregated data of daily GP visits during the Belgian summer period (May-September). A distributed lag nonlinear model (DLNM) with time-stratified conditional quasi-Poisson regression was used to account for the non-linear and delayed effect of temperature indicators (minimum, mean and maximum). We controlled for potential confounders such as particulate matter, humidity, and ozone.

RESULTS

The overall (lag0-14) association between heat and most of the outcomes was J-shaped, with an increased risk of disease observed at higher temperatures. The associations were more pronounced using the minimum temperatures indicator. Comparing the 99th (20 °C) to the minimum morbidity temperature (MMT) of the minimum temperature distribution during summer, the relative risk (RR) was significantly higher for heat-related general symptoms (RR = 1.30 [95 % CI: 1.07, 1.57]), otitis externa (RR = 4.87 [95 % CI:2.98, 7.98]), general heart problems (RR = 2.43 [95 % CI: 1.33, 4.42]), venous problems (RR = 2.48 [95 % CI:1.55, 3.96]), respiratory complaints (RR = 1.97 [95 % CI: 1.25, 3.09]), skin problems (RR = 3.26 [95 % CI: 2.51, 4.25]), and urinary infections (RR = 1.37 [95 % CI: 1.11, 1.69]). However, we did not find evidence for heat-related increases in gastrointestinal problems, cerebrovascular events, cardiovascular events, arrhythmia, mental health problems, upper respiratory problems and lower respiratory problems. An increased risk of allergy was observed when the minimum temperature reached 17.8 °C (RR = 1.50 [95 % CI: 1.23, 1.83]). Acute effects of heat were observed (largest effects at the first few lags).

SUMMARY

Our findings indicated that the occurrence of certain symptoms and illnesses during summer season is associated to high temperature or environmental exposures that are augmented by elevated temperatures. Overall, unlike hospitalization data, GP visits data provide broader population coverage, revealing a more accurate representation of heat-health association.

Association of ambient temperature with intentional self-harm and suicide death in Seoul: a case-crossover design with a distributed lag nonlinear model

Previous epidemiological studies have reported a short-term association between ambient temperature and suicide risk. To gain a clearer understanding of this association, it is essential to differentiate the risk factors for intentional self-harm (ISH) from those specifically associated with suicide deaths. Therefore, this study aims to examine whether the association between daily temperature and ISH or suicide deaths differs by age and sex. Between 2014 and 2019, cases of emergency room visits related to ISH and suicide deaths in Seoul were identified. A time-stratified case-crossover design was used to adjust for temporal trends and seasonal variation. A distributed lag nonlinear model was used to analyze the nonlinear and time-delayed effect of ambient temperature on ISH and suicide deaths. Positive associations were observed between temperature and both ISH and suicide deaths. For ISH, the relative risk (RR) was high at 1.17 (95% confidence interval (CI): 1.03, 1.34) for a temperature of 25.7 °C compared with 14.8 °C. The RR for suicide death was higher than those for ISH, at 1.43 (95% CI: 1.03, 2.00) for a temperature of 33.7 °C. These associations varied by age and sex, with males and females aged 35-64 years showing increased susceptibility to suicide deaths. This study provides detailed evidence that unusually high temperatures, both anomalous and out of season, may trigger suicidal behaviors, including both ISH and suicide deaths.

["Is there a Link Between Heat Waves and Mental Health Emergencies in the Emergency Department?"]

OBJECTIVE

There is evidence suggesting that climate change, coupled with an increase in the frequency and severity of heatwaves, affects mental health. The aim of this study was to investigate potential associations between high temperature and the utilization of an emergency department (ED) by individuals with psychiatric disorders.

METHODS

A retrospective analysis of all psychiatric emergency patients from 2015 to 2022 (N=15478) was conducted and compared with local temperature data.

RESULTS

Particularly during heatwaves, more psychiatric emergency patients presented to the ED.

CONCLUSION

Beyond the results identified during heatwaves, our extensive analysis of the examined ED revealed no additional significant effects of heat on psychiatric emergencies. This contradicts findings from other studies. Other systemic influences, such as the utilization of the ED during the Covid-19 pandemic, could have modified the results.

Prevention of suicides associated with global warming: perspectives from early career psychiatrists

Climate change poses significant challenges to global mental health, with potential consequences including increased rates of suicide and mental health disorders. Early Career Psychiatrists (ECPs) play a crucial role in addressing these challenges. The Climate Psychiatry Alliance, a group of psychiatrists dedicated to improving mental health amidst climate change, recognizes the importance of cultivating climate-aware ECPs. Training ECPs to become confident climate-aware clinicians enables them to effectively treat patients experiencing anxiety, depression, and PTSD in the context of climate-related distress. Together with other mental health professionals, ECPs can contribute to efforts by implementing strategies for monitoring and treating mental health problems arising from climate events. Additionally, they can raise awareness about the psychological consequences and risks of suicide associated with climate change. Collaboration among ECPs from various regions is essential in developing community-based approaches and reducing vulnerabilities. ECPs must prioritize supporting vulnerable populations by advocating for increased funding for mental health support and research in affected areas. Long-term solutions to address the mental health impacts of climate change and global warming should be pursued to mitigate future suicidality. Integrating climate considerations into local mental health programs and expanding psychological support services is crucial. By promoting emotional resilience and self-awareness, ECPs can contribute to building a more climate-resilient and mentally healthy society.

Youth Suicidality in the Context of Disasters

PURPOSE OF REVIEW

The purpose of this review is to summarize the current literature regarding youth suicidality (suicidal ideation, suicidal behavior, and completed suicide) in the context of disasters.

RECENT FINDINGS

There are fewer studies that examine the effect of disasters on suicidality specifically in children and youth than studies that focus on adults or general population. Numerous studies have reported on the effect of disasters on youth mental health in general without zeroing in on suicide risk. Some variables that have shown to increase suicide risk in children and youth after disasters include female gender, age at the time of disaster exposure, dependence on adults, attachments to places and caregivers, family functioning, and vulnerability to mistreatment. Several studies have demonstrated that youth suicidality fluctuates in response to disasters, at times increasing immediately post-disaster and at other times decreasing immediately post-disaster followed by an increase later. Exposure to natural disasters (e.g., earthquakes, typhoons, hurricanes, wildfires, and extremes of temperature and humidity), man-made disasters (e.g., armed conflict, global warming, and pollution), and unique disasters (e.g., the COVID-19 pandemic) have had significant impact on suicidality in children and adolescents. Although there are several promising interventions to mitigate the post-disaster suicide risk among youth, there is no consensus on a single intervention that is superior to others. More research is needed to study youth suicide risk in the context of disasters and develop culturally appropriate and evidence-based interventions.

Climate attribution of interpersonal violence: International evidence

Anthropogenic climate change is increasingly threatening interpersonal violence, yet global evidence for related impacts and potential transmission mechanisms remains limited. We examine whether and how climate change, particularly climate extremes, affects interpersonal violence. Using the panel data of 140 countries and regions from 2000 to 2019, we find that hot and wet extremes precipitated increase in homicide rates globally. Economic level, inequality, and resources scarcity were important intermediaries through which climate extremes affected homicide, while the direct effects still dominated the total effects. We then reveal the heterogeneous effects of climate extremes, further suggesting that poor countries and regions with relatively small contributions to climate change were particularly sensitive to climate extremes. These findings elucidate a strong climate-violence link, helping explain implications of facilitating violence prevention and mitigating climate change.

Estimating the burden of disease attributable to high ambient temperature across climate zones: methodological framework with a case study

BACKGROUND

With high temperature becoming an increasing health risk due to a changing climate, it is important to quantify the scale of the problem. However, estimating the burden of disease (BoD) attributable to high temperature can be challenging due to differences in risk patterns across geographical regions and data accessibility issues.

METHODS

We present a methodological framework that uses Köppen-Geiger climate zones to refine exposure levels and quantifies the difference between the burden observed due to high temperatures and what would have been observed if the population had been exposed to the theoretical minimum risk exposure distribution (TMRED). Our proposed method aligned with the Australian Burden of Disease Study and included two parts: (i) estimation of the population attributable fractions (PAF); and then (ii) estimation of the BoD attributable to high temperature. We use suicide and self-inflicted injuries in Australia as an example, with most frequent temperatures (MFTs) as the minimum risk exposure threshold (TMRED).

RESULTS

Our proposed framework to estimate the attributable BoD accounts for the importance of geographical variations of risk estimates between climate zones, and can be modified and adapted to other diseases and contexts that may be affected by high temperatures.

CONCLUSIONS

As the heat-related BoD may continue to increase in the future, this method is useful in estimating burdens across climate zones. This work may have important implications for preventive health measures, by enhancing the reproducibility and transparency of BoD research.

Assessing the Burden of Suicide Death Associated With Nonoptimum Temperature in a Changing Climate

Importance

Few studies have projected future suicide burden associated with daily temperatures in a warming climate.

Objectives

To assess the burden of suicide death associated with daily nonoptimal temperature and to project the change of suicide burden associated with nonoptimal temperature in different regions and seasons under various climate change scenarios.

Design, Setting, and Participants

Between January 1, 2013, and December 31, 2019, we conducted a time-stratified, case-control study among more than 430 000 individual suicide decedents from all counties in mainland China.

Exposures

Daily meteorological data were obtained from the European Centre for Medium-Range Weather Forecasts Reanalysis Fifth Generation (ERA5) reanalysis product. Historical and future temperature series were projected under 3 scenarios of greenhouse-gas emissions from 1980 to 2099, with 10 general circulation models.

Main Outcomes and Measures

The relative risk (RR) and burden of suicide death associated with nonoptimal temperature (ie, temperatures greater than or less than minimum-mortality temperature); the change of suicide burden associated with future climate warming in different regions and seasons under various climate change scenarios.

Results

Of 432 008 individuals (mean [SD] age; 57.6 [19.0] years; 253 093 male [58.6%]) who died by suicide, 85.8% (370 577) had a middle school education or less. The temperature-suicide associations were approximately linear, with increasing death risks at higher temperatures. The excess risk was more prominent among older adults (ie, ≥75 years; RR, 1.71; 95% CI, 1.46-1.99) and those with low education level (ie, middle school education or less; RR, 1.46; 95% CI, 1.36-1.57). There were 15.2% suicide deaths (95% estimated CI [eCI], 14.6%-15.6%) associated with nonoptimal temperature nationally. Consistent and drastic increases in excess suicide deaths over this century were predicted under the high-emission scenario, whereas a leveling-off trend after the mid-21st century was predicted under the medium- and low-emission scenarios. Nationally, compared with the historical period (1980-2009), excess suicide deaths were predicted to increase by 8.3% to 11.4% in the 2050s and 8.5% to 21.7% in the 2090s under the 3 scenarios. The projected percentage increments of excess suicide deaths were predicted to be greater in the South (55.0%; 95% eCI, 30.5%-85.6%) and in winter (54.5%; 95% eCI, 30.4%-77.0%) in the 2090s under the high-emission scenario.

Conclusions and Relevance

Findings of this nationwide case-control study suggest that higher temperature may be associated with the risk and burden of suicide death in China. These findings highlight the importance of implementing effective climate policies to reduce greenhouse gas emissions and tailoring public health policies to adapt to global warming.

The association between nation-level social and economic indices and suicide rates: A pilot study

Ever since the pioneering work of Emile Durkheim, it has been known that regional or national suicide rates can be influenced by a variety of social and economic factors. Recent research has found a robust association between two country-level economic indices-gross national product and unemployment rate-and suicide rates, particularly in men. However, the association between other country-level social indices-such as measures of social integration, inequality, environmental preservation and political freedom-and suicide rates has not been studied at the cross-national level. In the current study, national suicide rates for men and women were examined in relation to seven indices measuring subjective wellbeing, sustainable development, type of political regime, economic and gender inequality, and social capital. It was found that the Happy Planet Index, a composite measure of subjective wellbeing and sustainable development, was negatively associated with suicide rates independent of gender, and even after adjusting for possible confounding factors. Economic inequality was associated with suicide in men, and social capital was associated with suicide in women. Moreover, the strength and direction of the associations observed between socioeconomic indices and suicide varied across income groups. These results highlight the need for a closer evaluation of the link between large-scale ("macro") social factors and individual ("micro") psychological factors, as well as the importance of integrating these factors into suicide prevention programmes at the national level.

A Systematic Literature Review of the Impact of Climate Change on the Global Demand for Psychiatric Services

Climate Change (CC) imposes important global health risks, including on mental health (MH). They are related mostly to psychological suffering caused by climate-related events and to the heat-vulnerability caused by psychiatric disorders. This growing burden may press MH services worldwide, increasing demand on public and private systems in low-, middle-, and high-income countries. According to PRISMA, two independent reviewers searched four databases for papers published before May 2022 that associated climate-related events with healthcare demand for psychiatric conditions. Of the 7432 papers retrieved, we included 105. Only 29 were carried out in low- and middle-income countries. Twelve related the admission numbers to (i) extreme events, while 93 to (ii) meteorological factors-mostly heat. Emergency visits and hospitalizations were significantly higher during hot periods for MH disorders, especially until lag 5-7. Extreme events also caused more consultations. Suicide (completed or attempted), substance misuse, schizophrenia, mood, organic and neurotic disorders, and mortality were strongly affected by CC. This high healthcare demand is evidence of the burden patients may undergo. In addition, public and private services may face a shortage of financial and human resources. Finally, the increased use of healthcare facilities, in turn, intensifies greenhouse gas emissions, representing a self-enforcing cycle for CC. Further research is needed to better clarify how extreme events affect MH services and, in addition, if services in low- and middle-income countries are more intensely demanded by CC, as compared to richer countries.

Association between short-term exposure to extreme humidity and painful diabetic neuropathy: a case-crossover analysis

Painful diabetic neuropathy (PDN) is a common complication of diabetes mellitus, which reduces the quality of life. However, the association between PDN and environmental factors, especially ambient humidity, remains unclear. Therefore, this study investigated the impact of extreme humidity events on PDN. Data on PDN-related hospital admissions to two tertiary hospitals in Hefei, China (2014-2019) were obtained. A distributed lag non-linear model with a case-crossover design was used to quantitatively estimate the effects of ambient humidity on PDN, and the results were stratified by sex and age. The 1st, 10th, 90th, and 99th percentiles of relative humidity (RHU) were defined as extreme humidity, and the average relative humidity (74.94%) was set as the reference value. Non-linear exposure-response curves between the RHU and PDN cases were obtained. Extreme humidity (92%) had a significant effect on PDN with a relative risk (RR) of 1.13 (95% confidence interval (CI): 1.01-1.26) on a particular day, which increased with the RHU (RR: 1.21, 95% CI: 1.02-1.45 at 98% extreme humidity). Stratification analysis showed that women (RR: 1.38, 95% CI: 1.07-1.77) and patients aged < 65 years (RR: 1.26, 95% CI: 1.01-1.57) were highly susceptible to this effect on the same day. The results suggest that extreme humidity is a crucial trigger for PDN onset in diabetes patients. Furthermore, the effects vary with sex and age. This study provides detailed evidence of the adverse effects of extreme weather on diabetes patients.

Association between temperature and natural mortality in Belgium: Effect modification by individual characteristics and residential environment

BACKGROUND

There is strong evidence of mortality being associated to extreme temperatures but the extent to which individual or residential factors modulate this temperature vulnerability is less clear.

METHODS

We conducted a multi-city study with a time-stratified case-crossover design and used conditional logistic regression to examine the association between extreme temperatures and overall natural and cause-specific mortality. City-specific estimates were pooled using a random-effect meta-analysis to describe the global association. Cold and heat effects were assessed by comparing the mortality risks corresponding to the 2.5th and 97.5th percentiles of the daily temperature, respectively, with the minimum mortality temperature. For cold, we cumulated the risk over lags of 0 to 28 days before death and 0 to 7 days for heat. We carried out stratified analyses and assessed effect modification by individual characteristics, preexisting chronic health conditions and residential environment (population density, built-up area and air pollutants: PM2.5, NO2, O3 and black carbon) to identify more vulnerable population subgroups.

RESULTS

Based on 307,859 deaths from natural causes, we found significant cold effect (OR = 1.42, 95%CI: 1.30-1.57) and heat effect (OR = 1.17, 95%CI: 1.12-1.21) for overall natural mortality and for respiratory causes in particular. There were significant effects modifications for some health conditions: people with asthma were at higher risk for cold, and people with psychoses for heat. In addition, people with long or frequent hospital admissions in the year preceding death were at lower risk. Despite large uncertainties, there was suggestion of effect modification by air pollutants: the effect of heat was higher on more polluted days of O3 and black carbon, and a higher cold effect was observed on more polluted days of PM2.5 and NO2 while for O3, the effect was lower.

CONCLUSIONS

These findings allow for targeted planning of public-health measures aiming to prevent the effects of extreme temperatures.