Association of urban built environment and socioeconomic factors with suicide mortality in high-density cities: A case study of Hong Kong

Increased Suicide Mortality and Reduced Life Expectancy Associated With Ambient Heat Exposure

INTRODUCTION

Ambient heat exposure is a risk factor for suicide in many regions of the world. However, little is known about the extent to which life expectancy has been shortened by heat-related suicide deaths. This study aimed to evaluate the short-term effects of heat on suicide mortality and quantify the reduced life expectancy associated with heat in China.

METHODS

A time-stratified, case-crossover analysis in 2023 was performed during the warm season (May to September) from 2016 to 2020 to assess the short-term association between extreme heat (the 95th percentile of mean temperature) and suicide mortality in Anhui Province, China. A subgroup analysis was performed according to sex, age, marital status, suicide type, and region. The attributable fraction and years of life lost due to heat were calculated, and the heat-related life expectancy loss was estimated.

RESULTS

This study included 9,642 suicide deaths, with an average age of 62.4 years and 58.8% of suicides in males. Suicide risk was associated with an 80.7% increase (95% confidence interval [CI]: 21.4%-68.9%) after exposure to extreme heat (30.6°C) in comparison to daily minimum temperature (7.9°C). Subgroup analysis revealed that heat-related suicide risk was more prominent in the married population than in the unmarried population. Heat was estimated to be associated with 31.7% (95% CI: 18.0%-43.2%) of the suicides, corresponding to 7.0 years of loss in life expectancy for each decedent.

CONCLUSIONS

Heat exposure was associated with an increased risk of suicide and reduced life expectancy. However, further prospective studies are required to confirm this relationship.

Association between greenspace exposure and suicide-related outcomes across the lifespan: A systematic review

A growing number of studies have linked greenspace exposure to suicide, but findings are inconsistent. We conducted a systematic review on the associations between greenspace exposure and suicide-related outcomes (namely, suicide mortality, self-harm, and suicidal ideation) up until January 6, 2023. We used the Mixed Methods Appraisal Tool (or MMAT) to assess the quality of the included studies. In total, 23 studies met our inclusion criteria, consisting of 14 ecological, four cross-sectional, three longitudinal, and two experimental studies. Most studies were published in 2022 and conducted in Europe (n = 10), Asia (n = 7), and North America (n = 5), with one worldwide analysis. Various indicators were used to assess greenspace exposure including objective measures (e.g., level of surrounding greenness, quantity, structural features, tree canopy coverage), and greenspace use (e.g., duration and frequency). Suicide mortality was the most studied outcome (n = 14). Quality assessment showed that most (87 %) of the included observational studies used representative samples. Protective associations of exposure to greenspace were reported for suicide mortality (9/14 or 64 %), self-harm (n = 3/5 or 60 %) and suicidal ideation (n = 4/6 or 67 %), with nine or 36 % studies reporting no association. Most of the included studies adjusted for key covariates such as age, sex, and socioeconomic status at various aggregate levels (e.g., household, city). For greenspace exposure and suicide mortality, studies stratified by sex (n = 10) showed larger protective associations for females (n = 7) than for males (n = 4). However, the included studies showed high heterogeneity in terms of exposure indicators and greenspace definitions. Experimental studies and studies using youth samples were rare. While more research is warranted, preliminary findings suggest protective associations between greenspace exposure and suicide-related outcomes.

Integrating street view images and deep learning to explore the association between human perceptions of the built environment and cardiovascular disease in older adults

Understanding how built environment attributes affect health remains important. While many studies have explored the objective characteristics of built environments that affect health outcomes, few have examined the role of human perceptions of built environments on physical health. Baidu Street View images and computer vision technological advances have helped researchers overcome the constraints of traditional methods of measuring human perceptions (e.g., these methods are laborious, time-consuming, and costly), allowing for large-scale measurements of human perceptions. This study estimated human perceptions of the built environment (e.g., beauty, boredom, depression, safety, vitality, and wealth) by adopting Baidu Street View images and deep learning algorithms. Negative binomial regression models were employed to analyze the relationship between human perceptions and cardiovascular disease in older adults (e.g., ischemic heart disease and cerebrovascular disease). The results indicated that wealth perception is negatively related to the risk of cardiovascular disease. However, depression and vitality perceptions are positively associated with the risk of cardiovascular disease. Furthermore, we found no relationship between beauty, boredom, safety perceptions, and the risk of cardiovascular disease. Our findings highlight the importance of human perceptions in the development of healthy city planning and facilitate a comprehensive understanding of the relationship between built environment characteristics and health outcomes in older adults. They also demonstrate that street view images have the potential to provide insights into this complicated issue, assisting in the formulation of refined interventions and health policies.

Sunshine duration and risks of schizophrenia hospitalizations in main urban area: Do built environments modify the association?

BACKGROUND

Although studies have explored the relationship between sunshine duration and schizophrenia, the evidence was ambiguous. Different built environments may alter the effect of sunlight on schizophrenia, thus the purpose of this study was to investigate the effects of built environments on the sunshine duration-schizophrenia association.

MATERIALS AND METHODS

Daily schizophrenia hospitalizations data during 2017-2020 in Hefei's main urban area, China, and corresponding meteorological factors as well as ambient pollutants were collected. The impact of sunshine duration on schizophrenia admissions in urban areas was investigated using a generalized additive model combined with a distributed lagged nonlinear model. Additionally, the various modifying effects of different Building Density, Building Height, Normalized Vegetation Index, and Nighttime Light were also explored between sunshine duration and schizophrenia.

RESULTS

We observed that inadequate sunshine duration (<5.3 h) was associated with an increase in schizophrenia hospital admissions, with a maximum relative risk of 1.382 (95 % confidence interval (CI): 1.069-1.786) at 2.9 h. In turn, adequate sunshine duration reduced the risk of schizophrenia hospitalizations. Subgroup analyses indicated females and old patients were particularly vulnerable. In the case of insufficient sunshine duration, significant positive effects were noticed on schizophrenia risk at High-Building Density and High-Nighttime Light. Higher NDVI as well as Building Height were found to be associated with lower risks of schizophrenia.

CONCLUSIONS

Given that sunshine duration in various built environments might lead to distinct effects on schizophrenia hospitalizations. Our findings assist in identifying vulnerable populations that reside in particular areas, thus suggesting policymakers provide advice to mitigate the onset of schizophrenia by allocating healthcare resources rationally and avoiding adverse exposures to vulnerable populations timely.

[Climate change and mental health. Position paper of a task force of the DGPPN]

Climate change and the resulting higher frequency of extreme weather events have a direct negative impact on mental health. Natural disasters are particularly associated with an increase in the prevalence of depression, anxiety and posttraumatic stress disorder. Indirect consequences of climate change, such as food shortages, economic crises, violent conflicts and forced migration, additionally represent severe psychological risk and stress factors. Climate anxiety and solastalgia, the distress induced by environmental change, are new psychological syndromes in the face of the existential threat posed by the climate crisis. Accordingly, a sustainable psychiatry must prepare for increasing and changing demands. The principles of psychiatric treatment need to focus more on prevention to reduce the overall burden on the healthcare system. Waste of resources and CO₂ emissions in psychiatric treatment processes as well as infrastructure must be perceived and prevented. Psychiatric education, training and continuing education concepts should be expanded to include the topic of climate change in order to comprehensively inform and sensitize professionals, those affected and the public and to encourage climate-friendly and health-promoting behavior. More in-depth research is needed on the impact of climate change on mental health. The DGPPN becomes a sponsor and aims for climate neutrality by 2030 by committing to climate-friendly and energy-saving measures in the area of finance, in relation to the DGPPN congress as well as the DGPPN office.

Trends of suicide rates by gender and residence in China from 2002 to 2019

Objective

China has undergone tremendous social changes in the last few decades. This study aimed to research the trends of the suicide rates from 2002 to 2019, and to differentiate effects attributable to age, period, and cohort by gender and residence in China.

Methods

Suicide mortality data were obtained from China's Ministry of Health Vital Registration System. Joinpoint regression model was used to estimate the average annual percentage change (AAPC) of the suicide rates and ratios by gender and residence. The age-period-cohort framework was performed to analyze the underlying mechanisms for suicide mortality trends.

Results

Over the observation period, the significant decrease in suicide mortality rates in China for the economic development and urbanization was observed but to different degrees across gender and regional subgroups. The male-to-female ratio of suicide rates increased year by year (AAPC: 1.9%, 95% CI: 0.2% to 3.7%) while the urban-rural ratio changed little (AAPC: 0.9%, 95% CI: -1.8% to 3.7%). The age-period-cohort analysis revealed a marked increased effect of age and overall decreased effect of both period and cohort on suicide mortality rates. However, the recent cohort has presented an inversely increasing effect.

Conclusion

The suicide rate has fallen sharply in China which has undergone tremendous socioeconomic changes. The varied changes in the suicide rate of different residence-, gender-, and age-groups as well as the age, period, and cohort effect on suicide risk further indicate the relationship of development and the suicide rates may be neither static nor identical on different subgroups in a rapidly changing society.

The Impacts of Housing Characteristics and Built-Environment Features on Mental Health

In this study, we examined the relationships between housing characteristics, neighborhood built-environment features, and people's mental health in Hong Kong, an Asian city well known for its high-density and high-rise housing. The potential mediating effects of people's perceived living environment were also considered in the analysis. We collected data from 221 participants from two communities in Hong Kong, i.e., Sham Shui Po (SSP) and Tin Shui Wai (TSW), using a stratified random sampling approach. Big datasets were also used to derive relevant built-environment features at the street block level. We used structural equation modeling to explore the complex relationships among housing characteristics, built-environment features, and mental health. The results indicate that the associations between built-environment quality and people's mental health are weak. For communities with relatively poor housing conditions (i.e., SSP in this study), the impact of housing characteristics on mental health may be more direct; for communities with relatively good housing conditions (i.e., TSW in this study), the effect of housing characteristics on mental health may be indirect. Our findings shed light on the importance of considering different contexts in developing policies related to housing and built environment and mental health.

Predicting the effect of street environment on residents' mood states in large urban areas using machine learning and street view images

BACKGROUND

Researchers have demonstrated that the built environment is associated with mental health outcomes. However, evidence concerning the effects of street environments on mood in fast-growing Asian cities is scarce. Traditional questionnaires and interview methods are labor intensive and time consuming and pose challenges for accurately and efficiently evaluating the impact of urban-scale street environments on mood.

OBJECTIVE

This study aims to use street view images and machine learning methods to model the impact of street environments on mood states in a large urban area in Guangzhou, China, and to assess the effect of different street view elements on mood.

METHODS

A total of 199,754 street view images of Guangzhou were captured from Tencent Street View, and street elements were extracted by pyramid scene parsing network. Data on six mood state indicators (motivated, happy, positive-social emotion, focused, relaxed, and depressed) were collected from 1590 participants via an online platform called Assessing the Effects of Street Views on Mood. A machine learning approach was proposed to predict the effects of street environment on mood in large urban areas in Guangzhou. A series of statistical analyses including stepwise regression, ridge regression, and lasso regression were conducted to assess the effects of street view elements on mood.

RESULTS

Streets in urban fringe areas were more likely to produce motivated, happy, relaxed, and focused feelings in residents than those in city center areas. Conversely, areas in the city center, a high-density built environment, were more likely to produce depressive feelings. Street view elements have different effects on the six mood states. "Road" is a robust indicator positively correlated with the "motivated" indicator and negatively correlated with the "depressed" indicator. "Sky" is negatively associated with "positive-social emotion" and "depressed" but positively associated with "motivated". "Building" is a negative predictor for the "focused" and "happy" indicator but is positively related to the "depressed" indicator, while "vegetation" and "terrain" are the variables most robustly and positively correlated with all positive moods.

CONCLUSION

Our findings can help urban designers identify crucial areas of the city for optimization, and they have practical implications for urban planners seeking to build urban environments that foster better mental health.

Suicide Mortality Rate as a Sustainable Development Goal (SDG): A Bibliometric Analysis

Suicidal behaviors are a serious but potentially preventable cause of premature death. Increased awareness of the importance of mental health for global health has led to new initiatives, supported by the World Health Organization (WHO) and the United Nations (UN). The suicide mortality rate is one of the indicators covered in the UN's Sustainable Development Goal (SDG) 3. The aim of this study is to identify the scientific production and its temporal evolution related to the suicide mortality rate indicator in the context of mental disorders and as one of the SDG. A bibliometric analysis was performed in Scopus to assess the related research on suicide mortality rate, including on the context of the third SDG, from inception to September 2, 2020. The set of articles were analyzed for bibliometric measures. A total of 3126 documents about mental health and suicide mortality rate on the context of SDG were collected. Articles were the predominant type of literature on this area (78.3%), with significant expression on the last years, more evident around 2015, the year of adoption of SDGs. Despite a large volume of evidence, the debate about suicide mortality rate as an indicator of SDG is still very sparse suggesting a need for better consensus on its evaluation methods. This study presents useful characteristics for the formulation of new studies and provides specific targets for the construction or improvement of public policies on the context of the SDGs for further discussion on this strategy proposed by the UN.

Exploring multiple pathways and mediation effects of urban environmental factors for suicide prevention

Public health is threatened by air pollution and high temperature, especially in urban areas and areas impacted by climate change. Well-designed urban forms have co-benefits on promoting human health and mediating atmospheric environment-related threats (e.g., high temperature and air pollution). Previous studies overlooked these mediating effects of urban form on suicide mortality. This study used partial least squares modeling and countywide data in Taiwan to identify the crucial influences and pathways of urban environment, socioeconomic status, and diseases on suicide mortality. The model considered the impact of the characteristics of urban form (i.e., urban development intensity, land mix, and urban sprawl), urban industrial status (i.e., industrial level), urban greening (i.e., green coverage), disease (i.e., important diseases morbidity of human immunodeficiency virus [HIV], cerebrovascular disease [CVD], chronic liver disease and cirrhosis [CLDC], nephritis, nephrotic syndrome and nephrosis [NNSN], malignant tumor [MT]), socioeconomic status (i.e., income level and aging population rate), and the atmospheric environment (i.e., air pollution and high temperature) on suicide mortality. Optimizing land mix and minimizing urban development intensity and urban sprawl have been found to reduce suicide mortality. The mediating effect of urban form on suicide mortality originated from air pollution and high temperature, and mediating air pollution was greater than high temperature. Furthermore, industrial level, important diseases (HIV, CVD, CLDC, NNSN, and MT) morbidity, an aging population rate, air pollution, and high temperature were associated with an increase in suicide mortality, whereas green coverage and income level were associated with a reduction in suicide rates. The findings demonstrate that appropriate urban policy and urban planning may lower suicide mortality, be useful strategies for suicide prevention, and be a foundation for building a healthy city. Moreover, this study provides clarity on the complex relationship of suicide and the urban environment while identifying crucial factors.

A novel approach of creating sustainable urban planning solutions that optimise the local air quality and environmental equity in Helsinki, Finland: The CouSCOUS study protocol

Background

Air pollution is one of the major environmental challenges cities worldwide face today. Planning healthy environments for all future populations, whilst considering the ongoing demand for urbanisation and provisions needed to combat climate change, remains a difficult task.

Objective

To combine artificial intelligence (AI), atmospheric and social sciences to provide urban planning solutions that optimise local air quality by applying novel methods and taking into consideration population structures and traffic flows.

Methods

We will use high-resolution spatial data and linked electronic population cohort for Helsinki Metropolitan Area (Finland) to model (a) population dynamics and urban inequality related to air pollution; (b) detailed aerosol dynamics, aerosol and gas-phase chemistry together with detailed flow characteristics; (c) high-resolution traffic flow addressing dynamical changes at the city environment, such as accidents, construction work and unexpected congestion. Finally, we will fuse the information resulting from these models into an optimal city planning model balancing air quality, comfort, accessibility and travelling efficiency.

Comparing the space-time patterns of high-risk areas in different waves of COVID-19 in Hong Kong

This study compares the space-time patterns and characteristics of high-risk areas of COVID-19 transmission in Hong Kong between January 23 and April 14 (the first and second waves) and between July 6 and August 29 (the third wave). Using space-time scan statistics and the contact tracing data of individual confirmed cases, we detect the clusters of residences of, and places visited by, both imported and local cases. We also identify the built-environment and demographic characteristics of the high-risk areas during different waves of COVID-19. We find considerable differences in the space-time patterns and characteristics of high-risk residential areas between waves. However, venues and buildings visited by the confirmed cases in different waves have similar characteristics. The results can inform policymakers to target mitigation measures in high-risk areas and at vulnerable groups, and provide guidance to the public to avoid visiting and conducting activities at high-risk places.

A natural experiment reveals impacts of built environment on suicide rate: Developing an environmental theory of suicide

BACKGROUND

Suicide is a global challenge. Although it is clear that socioeconomic and demographic factors influence suicide rates, we know little about the impacts of the built environment on suicide rates.

METHODS

We investigated the relationship between characteristics of the built environment and suicide death rates over a 13-year period in 151 rent-only public housing communities in Hong Kong. The regulations of the public housing authority in Hong Kong constituted a natural experiment with minimal self-selection bias. We conducted hierarchical regression analyses and found that characteristics of the built environment were significantly associated with suicide rates after controlling for SES and demographic factors at the community level.

RESULTS

Three significant environmental factors were identified distance to the nearest urban center, distance to the nearest Mass Transit Railway station, and gross flat area per person.

CONCLUSION

These findings demonstrate a significant association between features of the built environment and suicide rates. They also suggest possible interventions that might reduce suicide through design, or redesign, of the built environment. Lastly, we propose an environmental theory of suicide based on the Interpersonal Theory of Suicide.

Long-term association between urban air ventilation and mortality in Hong Kong

While associations between population health outcomes and some urban design characteristics, such as green space, urban heat islands (UHI), and walkability, have been well studied, no prior studies have examined the association of urban air ventilation and health outcomes. This study used data from Hong Kong, a densely populated city, to explore the association between urban air ventilation and mortality during 2008-2014. Frontal area density (FAD), was used to measure urban ventilation, with higher FAD indicating poorer ventilation, due to structures blocking wind penetration. Negative binomial regression models were constructed to regress mortality counts for each 5-year age group, gender, and small area group, on small area level variables including green space density, population density and socioeconomic indicators. An interquartile range increase in FAD was significantly associated with a 10% (95% confidence interval (CI) 2%-19%, p = 0.019) increase in all-cause mortality and a 21% (95% CI: 2%-45%, p = 0.030) increase in asthma mortality, and non-significantly associated with a 9% (95% CI: 1%-19%, p = 0.073) in cardio-respiratory mortality. Better urban ventilation can help disperse vehicle-related pollutants and allow moderation of UHIs, and for a coastal city may allow moderation of cold temperatures. Urban planning should take ventilation into account. Further studies on urban ventilation and health outcomes from different settings are needed.