Mortality burden attributable to high and low ambient temperatures in China and its provinces: Results from the Global Burden of Disease Study 2019

Projections of Heat-Related Mortality in Chinese Cities: The Roles of Climate Change, Urbanization, Socioeconomic Adaptation, and Landscape-Level Strategies

BACKGROUND

Physiological heat strain induced by extreme temperatures in cities has led to significant heat-related deaths. Although socioeconomic adaptation is suggested to mitigate this issue, its effectiveness is limited. Conversely, there is a lack of comprehensive evaluation on the effectiveness of landscape-level strategies for mitigating heat-related deaths.

OBJECTIVES

We developed a comprehensive modeling framework to estimate the impacts of environmental stresses and mitigating strategies on heat-related deaths in China's cities from 2016 to 2055.

METHODS

The framework assesses future heat-related deaths through five experiments considering the influences of climate change, urbanization, socioeconomic adaptation, and landscape-level strategies. We used extrapolated region-specific exposure-response functions (ERF) and recent advancement of geo-statistics for public health to generate urban patch level ERF curves. We used these curves and temperature and population data to generate future heat-related deaths with a 1 -km resolution and conducted 5,000 Monte Carlo simulations for uncertainty analysis.

RESULTS

Our analyses estimated that heat-related mortality will increase from 136.5 ± 16.5 deaths per million in 2016 to 175.7 ± 27.5 deaths per million in 2055 under SSP2-RCP4.5 (shared socioeconomic pathways-representative concentration pathways) scenario and from 140.0 ± 21.4 deaths per million to 230.2 ± 38.7 deaths per million under SSP5-RCP8.5 scenario, despite socioeconomic adaptation and landscape-level strategies. Socioeconomic adaptation (reducing deaths by 18.4 - 64.1  per million ) and landscape-level strategies (reducing deaths by 45.6 - 51.3  per million ) significantly mitigate heat-related deaths with varying effectiveness across different income levels. Specifically, in high-income cities with dense populations, landscape-level strategies are 2.2-4.3 times more effective than socioeconomic adaptation. Within these cities, implementing the same landscape-level strategies in the high-density urban centers led to an additional reduction up to 4.9 - 6.8  deaths / km 2 in comparison with surrounding areas.

DISCUSSION

Our framework helps to systematically understand the effectiveness of landscape-level strategies in reducing heat-related mortality. Future sustainable city management should prioritize landscape-level strategies along with socioeconomic adaptation to support healthy and comfortable communities. https://doi.org/10.1289/EHP15010.

Global, regional, and national burden of older adult atopic dermatitis in 204 countries and territories worldwide

Background

With the aging global population, older adult atopic dermatitis (AD) is emerging as an increasingly significant health challenge. This study aimed to evaluate the global burden of older adult AD from 1990 to 2021 and to project its change to 2050.

Methods

The estimates and 95% uncertainty intervals of prevalence, incidence, and disability-adjusted life-years (DALYs) attributable to AD among individuals aged over 60 years were extracted from the Global Burden of Diseases (GBD) Study 2021. We used joinpoint regression analysis, decomposition analysis, cross-country inequality analysis, frontier analysis and prediction model to epidemiological analysis.

Results

From 1990 to 2021, the global prevalence of older adult AD increased to 11,009,630 cases (95% UI: 9,915,829 to 12,170,941), even as ASRs declined, which were primarily driven by population growth. It was observed that females and 75-79 years old had higher incidence rates. SDI relative and frontier analysis exhibited that incidence, prevalence and DALYs rates were positively correlated with SDI levels, while SDI-related inequalities had a significant decrease. Predictions up to 2050 anticipated increasing older adult AD incidence, prevalence, and DALYs numbers, while only age-standardized disability-adjusted life-year rates (ASDRs) were expected to decline.

Conclusion

The burden of older adult AD varied by genders, age groups, regions, countries and climatic conditions. Although the ASRs had shown a decline over time, the burden of older adult AD remained significant, especially in regions with high SDI levels. In the future, the burden of older adult AD was projected to continue rising until 2050, thereby targeted interventions and public health strategies were needed to address this trend.

Burden trends and future predictions for hypertensive heart disease attributable to non-optimal temperatures in the older adults amidst climate change, 1990-2021

Background

Hypertensive heart disease (HHD) is a significant form of end-organ damage caused by hypertension, with profound impacts on global health and quality of life. Temperature anomalies driven by climate change, particularly extremes of heat and cold, are increasingly recognized as major contributors to the cardiovascular disease burden, notably impacting HHD. However, the specific spatiotemporal trends and gender-based differences in the burden of non-optimal temperatures on older adults HHD patients remain insufficiently explored. This study aims to evaluate the regional, gender-specific trends in the burden of HHD attributed to non-optimal temperatures among the older adults from 1990 to 2021, and to project future trends in HHD burden under climate-induced temperature anomalies from 2022 to 2050.

Methods

Data were sourced from the Global Burden of Disease Study (GBD 2021), which provides estimates of mortality and disability-adjusted life years (DALYs) at global, regional, and national levels. Age-standardized rates (ASR) and estimated annual percentage changes (EAPC) were analyzed. Future burden projections were modeled using age-period-cohort (APC) and Bayesian APC models to assess temperature impact by gender and age differences. Data analysis was conducted using R and STATA, examining the variations in temperature effects by gender and age.

Results

Between 1990 and 2021, cold-related HHD burden among the older adults significantly exceeded that of heat-related burden. However, heat-related HHD burden demonstrated a marked upward trend, projected to continue rising over the next two decades, particularly in low-income and tropical regions. Gender-specific analysis revealed that cold-related HHD burden was more pronounced in women, while heat-related burden was notably higher in men. Additionally, male heat-related HHD mortality rates have shown a substantial increase over the past 30 years, whereas female rates have exhibited a comparatively modest decline.

Conclusion

Although cold remains the dominant non-optimal temperature factor, rising global temperatures suggest an increasing burden of heat-related HHD among the older adults. Efforts should prioritize strengthening resilience in vulnerable regions and populations, with targeted interventions to mitigate future health risks associated with temperature extremes.

A time-stratified, case-crossover study of heat exposure and perinatal mortality from 16 hospitals in sub-Saharan Africa

Growing evidence suggests that extreme heat events affect both pregnant women and their infants, but few studies are available from sub-Saharan Africa. Using data from 138,015 singleton births in 16 hospitals in Benin, Malawi, Tanzania and Uganda, we investigated the association between extreme heat and early perinatal deaths, including antepartum and intrapartum stillbirths, and deaths within 24 h after birth using a time-stratified case-crossover design. We observed an association between an increase from the 75th to the 99th percentile in mean temperature 1 week (lag 0-6 d) before childbirth and perinatal mortality (odds ratio (OR) = 1.34 (95% confidence interval (CI) 1.01-1.78)). The estimates for stillbirths were similarly positive, but CIs included unity: OR = 1.29 (95% CI 0.95-1.77) for all stillbirths, OR = 1.18 (95% CI 0.71-1.95) for antepartum stillbirths and OR = 1.64 (95% CI 0.74-3.63) for intrapartum stillbirths. The cumulative exposure-response curve suggested that the steepest slopes for heat for intrapartum stillbirths and associations were stronger during the hottest seasons. We conclude that short-term heat exposure may increase mortality risks, particularly for intrapartum stillbirths, raising the importance of improved intrapartum care.

Impact of Ambient Temperature on Mortality Burden and Spatial Heterogeneity in 16 Prefecture-Level Cities of a Low-Latitude Plateau Area in Yunnan Province: Time-Series Study

Background

The relation between climate change and human health has become one of the major worldwide public health issues. However, the evidence for low-latitude plateau regions is limited, where the climate is unique and diverse with a complex geography and topography.

objectives

This study aimed to evaluate the effect of ambient temperature on the mortality burden of nonaccidental deaths in Yunnan Province and to further explore its spatial heterogeneity among different regions.

Methods

We collected mortality and meteorological data from all 129 counties in Yunnan Province from 2014 to 2020, and 16 prefecture-level cities were analyzed as units. A distributed lagged nonlinear model was used to estimate the effect of temperature exposure on years of life lost (YLL) for nonaccidental deaths in each prefecture-level city. The attributable fraction of YLL due to ambient temperature was calculated. A multivariate meta-analysis was used to obtain an overall aggregated estimate of effects, and spatial heterogeneity among 16 prefecture-level cities was evaluated by adjusting the city-specific geographical characteristics, demographic characteristics, economic factors, and health resources factors.

Results

The temperature-YLL association was nonlinear and followed slide-shaped curves in all regions. The cumulative cold and heat effect estimates along lag 0-21 days on YLL for nonaccidental deaths were 403.16 (95% empirical confidence interval [eCI] 148.14-615.18) and 247.83 (95% eCI 45.73-418.85), respectively. The attributable fraction for nonaccidental mortality due to daily mean temperature was 7.45% (95% eCI 3.73%-10.38%). Cold temperature was responsible for most of the mortality burden (4.61%, 95% eCI 1.70-7.04), whereas the burden due to heat was 2.84% (95% eCI 0.58-4.83). The vulnerable subpopulations include male individuals, people aged <75 years, people with education below junior college level, farmers, nonmarried individuals, and ethnic minorities. In the cause-specific subgroup analysis, the total attributable fraction (%) for mean temperature was 13.97% (95% eCI 6.70-14.02) for heart disease, 11.12% (95% eCI 2.52-16.82) for respiratory disease, 10.85% (95% eCI 6.70-14.02) for cardiovascular disease, and 10.13% (95% eCI 6.03-13.18) for stroke. The attributable risk of cold effect for cardiovascular disease was higher than that for respiratory disease cause of death (9.71% vs 4.54%). Furthermore, we found 48.2% heterogeneity in the effect of mean temperature on YLL after considering the inherent characteristics of the 16 prefecture-level cities, with urbanization rate accounting for the highest proportion of heterogeneity (15.7%) among urban characteristics.

Conclusions

This study suggests that the cold effect dominated the total effect of temperature on mortality burden in Yunnan Province, and its effect was heterogeneous among different regions, which provides a basis for spatial planning and health policy formulation for disease prevention.

Risk factors associated with heatwave mortality in Chinese adults over 65 years

Aging populations are susceptible to heat-related mortality because of physiological factors and comorbidities. However, the understanding of individual vulnerabilities in the aging population is incomplete. In the Chinese Longitudinal Healthy Longevity Survey, we assessed daily heatwave exposure individually for 13,527 participants (median age = 89 years) and 3,249 summer mortalities during follow-up from 2008 to 2018. The mortality risk during heatwave days according to relative temperature is approximately doubled (hazard ratio (HR) range = 1.78-1.98). We found that heatwave mortality risks were increased for individuals with functional declines in mobility (HR range = 2.32-3.20), dependency in activities of daily living (HR range = 2.22-3.27), cognitive impairment (HR = 2.22) and social isolation reflected by having nobody to ask for help during difficulties (HR range = 2.14-10.21). Contrary to current understanding, older age was not predictive of heatwave mortality risk after accounting for individual functional declines; no statistical differences were detected according to sex. Beyond age as a risk factor, our findings emphasize that functional aging is an underlying factor in enhancing heatwave resilience. Assessment of functional decline and implementing care strategies are crucial for targeted prevention of mortality during heatwaves.

Heat and Cardiovascular Mortality: An Epidemiological Perspective

As global temperatures rise, extreme heat events are projected to become more frequent and intense. Extreme heat causes a wide range of health effects, including an overall increase in morbidity and mortality. It is important to note that while there is sufficient epidemiological evidence for heat-related increases in all-cause mortality, evidence on the association between heat and cause-specific deaths such as cardiovascular disease (CVD) mortality (and its more specific causes) is limited, with inconsistent findings. Existing systematic reviews and meta-analyses of epidemiological studies on heat and CVD mortality have summarized the available evidence. However, the target audience of such reviews is mainly limited to the specific field of environmental epidemiology. This overarching perspective aims to provide health professionals with a comprehensive overview of recent epidemiological evidence of how extreme heat is associated with CVD mortality. The rationale behind this broad perspective is that a better understanding of the effect of extreme heat on CVD mortality will help CVD health professionals optimize their plans to adapt to the changes brought about by climate change and heat events. To policymakers, this perspective would help formulate targeted mitigation, strengthen early warning systems, and develop better adaptation strategies. Despite the heterogeneity in evidence worldwide, due in part to different climatic conditions and population dynamics, there is a clear link between heat and CVD mortality. The risk has often been found to be higher in vulnerable subgroups, including older people, people with preexisting conditions, and the socioeconomically deprived. This perspective also highlights the lack of evidence from low- and middle-income countries and focuses on cause-specific CVD deaths. In addition, the perspective highlights the temporal changes in heat-related CVD deaths as well as the interactive effect of heat with other environmental factors and the potential biological pathways. Importantly, these various aspects of epidemiological studies have never been fully investigated and, therefore, the true extent of the impact of heat on CVD deaths remains largely unknown. Furthermore, this perspective also highlights the research gaps in epidemiological studies and the potential solutions to generate more robust evidence on the future consequences of heat on CVD deaths.

Health impacts of a cold wave and its economic loss assessment in China's high-altitude city, Xining

OBJECTIVE

Amidst climate change, extensive research has centered on the health impacts of heatwaves, yet the consequences of cold spells, particularly in cooler, higher-altitude regions, remain under-explored.

METHODS

Analyzing climatic data and non-accidental mortality in Xining, China's second-highest provincial capital, from 2016 to 2020, this study defines cold spells as daily mean temperatures below the 10th, 7.5th, or 5th percentiles for 2-4 consecutive days. A time-stratified case-crossover approach and distributional lag nonlinear modeling were used to assess the link between cold spells and mortality, calculating attributable fractions (AFs) and numbers (ANs) of deaths. The study also examined the impact of cold spells over different periods and analyzed the value of a statistical life (VSL) loss in 2018, a year with frequent cold spells. Stratified analyses by sex, age, and education level were conducted.

RESULTS

A significant association was found between cold spells and non-accidental mortality, with a relative risk of 1.548 (95% CI: 1.300, 1.845). The AF was 33.48%, with an AN of 9,196 deaths during the study's cold period. A declining trend in mortality risk was observed from 2019-2020. The 2018 VSL was approximately 2.875 billion CNY, about 1.75% of Xining's GDP. Higher risks were noted among males, individuals aged ≥ 65, and those with lower education levels.

CONCLUSION

The findings underscore the vulnerability and economic losses of high-altitude cities to cold spells. Implementing interventions such as improved heating, educational programs, and community support is vital for mitigating these adverse health effects.

Community-Level Practice Checklists for Health Protection During Cold Spells in China

Communities play a crucial role in protecting the health of vulnerable populations such as the elderly, low-income groups, and high-risk individuals during cold spells. However, current strategies for responding to cold spells primarily consist of programmatic policies that lack practicality, specificity, and detailed implementation guidelines for community workers. Therefore, this study aims to identify and analyze the challenges faced by communities in responding to cold spells, review international experiences, and develop a set of practical checklists for community-level health protection. These checklists will assist community workers and volunteers in effectively preparing for, responding to, and recovering from cold spells.

Trade-offs between cold protection and air pollution-induced mortality of China's heating policy

The winter heating policy in northern China was designed to safeguard households from the harsh subfreezing temperatures. However, it has inadvertently resulted in seasonal spikes in air pollution levels because of the reliance on coal as an energy source. While the loss of life years attributable to mortality from air pollution caused by winter heating has been estimated, the beneficial effect of protection from cold temperatures has not been assessed, primarily due to a lack of individual-level data linking these variables. Our study aims to address this research gap. We provide individual-level empirical evidence that quantifies the impact of protection from cold temperatures and air pollution on mortality, studying 5,334 older adults living around the Huai River during the period between 2000 and 2018. Our adjusted Cox-proportional hazard models show that winter heating was associated with a 22% lower mortality rate (95% CI: 16-28%). Individuals residing in areas without access to winter heating are subjected to heightened mortality risks during periods of cold temperatures. The protective effect is offset by a 27.8% rise attributed to elevated PM2.5 levels. Our results imply that the equilibrium between the effects of these two factors is achieved when PM2.5 concentration exceeds 24.3 µg/m3 (95% CI: 18.4-30.2). Our research suggests that while the existing winter heating policy significantly mitigates winter mortality by lessening the detrimental effects of cold temperatures, future air pollution reduction could provide further health benefits.

China's public health initiatives for climate change adaptation

China's health gains over the past decades face potential reversals if climate change adaptation is not prioritized. China's temperature rise surpasses the global average due to urban heat islands and ecological changes, and demands urgent actions to safeguard public health. Effective adaptation need to consider China's urbanization trends, underlying non-communicable diseases, an aging population, and future pandemic threats. Climate change adaptation initiatives and strategies include urban green space, healthy indoor environments, spatial planning for cities, advance location-specific early warning systems for extreme weather events, and a holistic approach for linking carbon neutrality to health co-benefits. Innovation and technology uptake is a crucial opportunity. China's successful climate adaptation can foster international collaboration regionally and beyond.

Spatial Patterns of Gallbladder and Biliary Tract Carcinoma in China From 1990 to 2019: An Analysis at the Provincial Level

Background Despite a high rate of fatal malignancy, little is known regarding the spatial and temporal patterns of the disease burden of gallbladder and biliary tract carcinoma in China, especially at the provincial level. Methodology Using data from the 2019 Global Burden of Diseases, Injuries, and Risk Factors Study, we estimated the temporal trend of the disease burden of gallbladder and biliary tract carcinoma from 1990 to 2019 as well as its incidence, mortality, prevalence, and disability-adjusted life-years (DALYs). We estimated the spatial pattern of the disease burden of gallbladder and biliary tract carcinoma at the provincial level. Results The disease burden of gallbladder and biliary tract carcinoma significantly increased from 1990 to 2019 in China. The age-standardized incidence, prevalence, mortality, and DALYs increased by 28.3%, 50.5%, 13.0%, and 7.0%, respectively. The disease burden of gallbladder carcinoma revealed substantial heterogeneity at the provincial level with a higher disease burden in developed provinces or cities than in developing provinces. The disease burden of gallbladder and biliary tract carcinoma was also heavier among males than among females (e.g., age-standardized DALYs: 42.60 per 100,000 people among males vs. 33.57 per 100,000 people among females in 2019). Conclusions The disease burden of gallbladder and biliary tract carcinoma has shown rapid changes during the past three decades, with a higher burden in economically advantaged regions than in disadvantaged regions in China. New public health policies and initiatives are needed to address this rising disease burden.

National situation, trends, and predictions of disease burden of atopic dermatitis in Chinese children and adolescents

Background

Atopic dermatitis (AD) is an important global health problem affecting children and adolescents and detailed national information of disease burden in China is lacking. We aimed to evaluate the national disease burden of AD in Chinese children and adolescent, to provide the temporal trends over the past 30 years and to predict the burden for the next 10 years.

Methods

The data of AD in China, including incidence, prevalence, and DALY, and population data were obtained from the Global Burden of Disease Study 2019 (GBD study 2019), which were estimated using the DisMod-MR 2.1. We analyzed the three measures by age and sex; the age groups were <5 years, 5-9 years, 10-14 years, and 15-19 years. The joinpoint regression analyses was conducted to assess the temporal trends from 1990 to 2019. The Bayesian age-period cohort (BAPC) model was used to predict measures from 2020 to 2030.

Results

In 2019, the highest incidence case and rate were observed in <5 years group; for prevalence and disability adjusted life year (DALY), the groups of <5 years and 5-9 years showed similar higher levels and the groups of 10-14 years and 15-19 years had similar relatively lower levels. Overall, the male-to-female ratios were >1 in <5 years group and <1 in 10-14 and 15-19 age groups. The trend analyses found an overall trend of decrease in cases of the three measures; in recent about 3 years, slight increase trends were shown in cases and rates of the three measures in <5 years group. The prediction analyses found a slight decreasing trend for cases of these measures and a slight increasing trend for rates of these measures in the <5 years group in the next 10 years; the 5-9 years group was predicted to increase slightly in rates of the three measures.

Conclusion

In conclusion, the groups of <5 years and 5-9 years are two important populations that need targeted measures to reduce disease burden of AD in China. Regarding sex disparity, we should pay more attention to males in <5 years group and to females in 10-19 years group.

Time trends in cardiovascular disease mortality attributable to non-optimal temperatures in China: An age-period-cohort analysis using the Global Burden of Disease Study 2019

Background

Associations between non-optimal temperatures and cardiovascular disease (CVD) mortality risk have been previously reported, yet the trends of CVD mortality attributable to non-optimal temperatures remain unclear in China. We analyzed trends in CVD mortality attributable to non-optimal temperatures and associations with age, period, and birth cohort.

Methods

Data were obtained from the Global Burden of Disease Study (GBD) 2019. Joinpoint regression analysis was used to calculate annual percent change (APC) and average annual percent change (AAPC) from 1990 to 2019. We used the age-period-cohort model to analyze age, period, and cohort effects in CVD mortality attributable to non-optimal temperatures between 1990 and 2019.

Results

The age-standardized mortality rate (ASMR) of CVD attributable to non-optimal temperature generally declined in China from 1990 to 2019, whereas ischemic heart disease (IHD) increased slightly. Low temperatures have a greater death burden than high temperatures, but the death burden from high temperatures showed steady increases. Joinpoint regression analysis showed that CVD mortality decreased in all age groups except for IHD, and the decreases were greater in females than in males. The mortality of CVD attributable to non-optimal temperatures of males was higher than females. The mortality rate showed an upwards trend with age across all CVD categories. Period risks were generally found in unfavorable trends. The cohort effects showed a progressive downward trend during the entire period.

Conclusion

Although there have been reductions in CVD mortality attributable to non-optimum temperatures, the mortality of IHD has increased and the burden from non-optimal temperatures remains high in China. In the context of global climate change, our results call for more attention and strategies to address climate change that protect human health from non-optimal temperatures.