Mental health impacts of environmental exposures: A scoping review of evaluative instruments

To date, much of the health focus of environmental policy has been on preventing physical health impacts of environmental exposures. Recent research has however highlighted increasingly concurrent mental health effects and its consideration is an emerging requirement for many governments and their agencies, yet there are limited universal mental health assessment tools for environmental exposures. This paper details the findings of a scoping review that evaluated assessment tools used to measure psychological impacts from environmental exposures and pollution, as reported in recent peer-reviewed literature (2000-2022). Across the 126 papers identified in our review, a wide range of tools to assess mental health impact were identified. We document a clear recent upswing of research interest in the mental and psychological impacts of environmental exposures, and an overarching concern for air pollution from industry, traffic, and fires. A majority of studies utilised standardised assessment instruments, but there was little consistency in the way that these were combined or deployed. The dominant mental health outcomes of interest in these studies were depression, anxiety, and mental and psychiatric health. The findings of the review identify a need and opportunity to develop a best-practice approach to consistently assess the mental health impacts arising from environmental exposures. Future work is needed to define the most appropriate choice and application of assessment tools to evaluate adverse mental health impacts from environmental exposures. This will support a more universal, coordinated and cross-jurisdiction approach for the assessment, quantification and targeted response to addressing mental health impacts arising from environmental exposures.

Mental illness and increased vulnerability to negative health effects from extreme heat events: a systematic review

RATIONALE

Across countries, extreme heat events are projected to increase in frequency and intensity because of climate change. Exposure to extreme heat events can have a substantial negative impact on human health, and extant research suggests that individuals with mental illness are particularly vulnerable. To date, there has been no review of evidence regarding this vulnerability to inform response strategies and future research.

OBJECTIVE

A systematic review was undertaken to investigate mental illness as an effect modifier of the relationship between heat exposure and morbidity or mortality.

METHODS

Six databases (Medline, Embase, Global Health, PsychInfo, CINAHL and Scopus) were searched for studies published between the years 2000 to 2022. Twenty-two observational studies that met the inclusion criteria were investigated through narrative synthesis. The RoBANS tool, ROBIS and GRADE were used to assess the certainty of evidence including the risk of bias.

RESULTS

Individuals with mental illness experience worse morbidity and mortality outcomes compared to their counterparts without mental illness in all studies investigating high temperature over a single day. This did not hold for studies examining heatwaves, which reported mixed findings.

CONCLUSIONS AND IMPLICATIONS

People with diagnosed mental illness should be targeted for policy and service attention during high temperature days. Further research should investigate specific mental illness and adjust for a wider range of confounding factors.

Parental co-residence and young adults' mental health

The growing trend towards young adults staying in the parental home has garnered much recent scholarly interest. However, less is known about which young adults are living at home, and the impacts this has over young adults' lives. Using The Household, Income and Labour Dynamics in Australia (HILDA) dataset, this study examines the profiles of co-residing young adults and how these have changed over the first two decades of the 21st century. It then analyses the associations between co-residence and young adults' mental health, applying a propensity score modelling approach to determine differences in mental health between young adults living at home and their counterparts living independently. Results indicate that rates of co-residence have increased over the 2000s, most steeply amongst those residing outside of major cities (by 46%), older adults (by 36%), females (by 28%), and low-income groups (by 10%). Findings show a significant negative association between co-residence and mental health (a 4-point difference on the 100-point scale, 95% CI -5.93, -2.14). However, the greatest differential in mental health between co-resident and independent young adults is observed amongst those for whom rates of co-residence have increased most dramatically, i.e., females and older adults (a 6-point difference in mental health) and residents of regional and rural areas (a 5-point difference in mental health). We situate this discussion in the context of intensifying housing market constraints, considering how the transformation of the Australian housing system into a vehicle for wealth accumulation has generated barriers to residential independence.

An Australian housing conditions data infrastructure

For the past two decades, researchers and policy makers have known very little about conditions within Australia's housing stock due to a lack of systematic and reliable data. In 2022, a collaboration of Australian universities and researchers commissioned a large survey of 22,550 private rental, social rental and homeowner households to build a data infrastructure on the household and demographic characteristics, housing quality and conditions in the Australian housing stock. This is the third and largest instalment in a national series of housing conditions data infrastructures.

Mapping social vulnerability indicators to understand the health impacts of climate change: a scoping review

The need to assess and measure how social vulnerability influences the health impacts of climate change has resulted in a rapidly growing body of research literature. To date, there has been no overarching, systematic examination of where this evidence is concentrated and what inferences can be made. This scoping review provides an overview of studies published between 2012 and 2022 on social vulnerability to the negative health effects of climate change. Of the 2115 studies identified from four bibliographic databases (Scopus, Web of Science, PubMed, and CAB Direct), 230 that considered indicators of social vulnerability to climate change impacts on health outcomes were selected for review. Frequency and thematic analyses were conducted to establish the scope of the social vulnerability indicators, climate change impacts, and health conditions studied, and the substantive themes and findings of this research. 113 indicators of social vulnerability covering 15 themes were identified, with a small set of indicators receiving most of the research attention, including age, sex, ethnicity, education, income, poverty, unemployment, access to green and blue spaces, access to health services, social isolation, and population density. The results reveal an undertheorisation and few indicators that conceptualise and operationalise social vulnerability beyond individual sociodemographic characteristics by identifying structural and institutional dimensions of vulnerability, and a preponderance of social vulnerability research in high-income countries. This Review highlights the need for future research, data infrastructure, and policy attention to address structural, institutional, and sociopolitical conditions, which will better support climate resilience and adaptation planning.

The total health gains and cost savings of eradicating cold housing in Australia

BACKGROUND

Cold indoor temperature (<18 °C) is associated with hypertension-related and respiratory disease, depression, and anxiety. We estimate total health, health expenditure and income impacts of permanently lifting the temperature in living areas of the home to 18 °C in cold homes in South-eastern Australia (N = 17 million).

METHODS

A proportional multistate lifetable model was used to estimate health adjusted life years (HALYs), health expenditure and income earnings, over the remainder of the lifespan of the population alive in 2021 (3% discount rate). Multiple data were integrated including the prevalence of cold housing (5.87%; mean temperature 15 °C), the effect of temperature to hypertension-related, respiratory disease, depression and anxiety.

FINDINGS

Eradicating cold housing was predicted to lead to 89,600 (95% UI 47,700 to 177,000) lifetime HALYs gained over the population's remaining lifespan, nearly half of which occurred from 2021 to 2040. Respiratory disease (32.4%) and mental illness (60.6%) made large contributions to HALYs gained, but also had large uncertainty (95% UI 30.0%-42.9% and 45.1%-64.6%, respectively) due to uncertain estimates of their magnitude of causal association with cold housing. Health gains per capita were 6.1 times greater (95% UI 4.7 to 8.1) among the most compared to least deprived quintile. From 2021 to 2040, health expenditure decreased by AUD$0.87 billion (0.35-1.98) and income earnings increased by AUD$4.35 billion (1.89-9.81).

INTERPRETATION

Eliminating cold housing would lead to substantial health gains, reductions in health inequalities, savings in health expenditure, and productivity gains. Next steps require research to reduce uncertainty about the magnitude of causal associations of cold with mental and respiratory health.

Group A Streptococcus Vaccine Targeting the Erythrogenic Toxins SpeA and SpeB Is Safe and Immunogenic in Rabbits and Does Not Induce Antibodies Associated with Autoimmunity

Group A streptococcus (GAS) is a global pathogen associated with significant morbidity and mortality for which there is currently no licensed vaccine. Vaccine development has been slow, mostly due to safety concerns regarding streptococcal antigens associated with autoimmunity and related complications. For a GAS vaccine to be safe, it must be ensured that the antigens used in the vaccine do not elicit an antibody response that can cross-react with host tissues. In this study, we evaluated the safety of our GAS vaccine candidate called VaxiStrep in New Zealand White rabbits. VaxiStrep is a recombinant fusion protein comprised of streptococcal pyrogenic exotoxin A (SpeA) and exotoxin B (SpeB), also known as erythrogenic toxins, adsorbed to an aluminum adjuvant. The vaccine elicited a robust immune response against the two toxins in the rabbits without any adverse events or toxicity. No signs of autoimmune pathology were detected in the rabbits' brains, hearts, and kidneys via immunohistochemistry, and serum antibodies did not cross-react with cardiac or neuronal tissue proteins associated with rheumatic heart disease or Sydenham chorea (SC). This study further confirms that VaxiStrep does not elicit autoantibodies and is safe to be tested in a first-in-human trial.

Housing typologies and asthma: a scoping review

Asthma is related to triggers within the home. Although it is recognised that triggers likely occur due to characteristics of housing, these characteristics have not been comprehensively reviewed, and there is a paucity of housing-focused interventions to reduce asthma and asthma symptoms. Following five steps identified by Arksey and O'Malley, we conducted a scoping review of published evidence on the associations between asthma and housing characteristics. We searched three electronic databases (PubMed, Scopus, Web of Science), identifying 33 studies that met our inclusion criteria. Through an iterative approach, we identified nine housing characteristics relevant to asthma onset or exacerbation, categorised as relating to the surrounding environment (location), the house itself (dwelling), or to conditions inside the home (occupancy). We conceptualise these three levels through a housing typologies framework. This facilitates the mapping of housing characteristics, and visualises how they can cluster and overlap to exacerbate asthma or asthma symptoms. Of the three levels in our framework, associations between asthma and locational features were evidenced most clearly in the literature reviewed. Within this category, environmental pollutants (and particularly air pollutants) were identified as a potentially important risk factor for asthma. Studies concerning associations between dwelling features and occupancy features and asthma reported inconsistent results, highlighting the need for greater research in these areas. Interpreting housing-related asthma triggers through this framework paves the way for the identification and targeting of typologies of housing that might adversely affect asthma, thus addressing multiple characteristics in tandem rather than as isolated elements.

Cold housing environments: defining the problem for an appropriate policy response

Researchers across disciplines are increasing attention to cold housing environments. Public health, environmental and social sciences, architecture, and engineering each define and measure cold housing environments differently. Lack of standardisation hinders our ability to combine evidence, determine prevalence, understand who is most at risk--and to formulate policy responses. We conducted a systematic, cross-disciplinary review of literature to document the measures used. We examined benefits and limitations of each approach and propose a conceptualisation of cold housing: where temperature is too low to support optimal health and wellbeing of inhabitants, measured using one or a combination of economic, 'objective', or subjective approaches. More accurate data on home temperatures for all population groups, combined with an understanding of factors leading to cold homes, will enable appropriate policy response to reduce adverse health effects and costs. Policies targeting better building standards and energy subsidies both improve temperature conditions in housing environments.

Green and blue spaces, COVID-19 lockdowns, and mental health: An Australian population-based longitudinal analysis

Australia experienced some of the world's longest and most stringent lockdowns during the COVID-19 pandemic. While lockdown measures had consequences for mental health, investigation is lacking on the potential for green and blue space coverage within people's local environments to ameliorate the impact of lockdowns with varied lengths using longitudinal cohorts. This study examined the impact of lockdown durations on population mental health and tests the effect modification of neighbourhood green and inland and coastal blue space coverage in metropolitan areas. We merged population-based longitudinal data on more than 11,000 individuals collected over a ten-year period from 2012 to 2021 with national land use data describing green and blue space coverage. We used fixed effect models to estimate the relationship between lockdowns (with different durations and staggered introduction) and mental health, controlling for sociodemographic, health, and geographical confounders, and tested the significance of effect modification of green and blue space. Results show that extended lockdowns led to considerably larger decreases in mental health (COVID-y1: -2.66, 95%CI: -3.43, -1.89; COVID-y2: -2.65, 95%CI: -3.33, -1.97) relative to short lockdowns. The mental health effect of lockdowns was smaller where green spaces and inland and coastal blue spaces were available. Effect modification was statistically significant for green space, with smaller negative mental health effects observed where there was sizeable green space coverage, particularly during long lockdowns (COVID-y1: -2.69, 95%CI: -3.63, -1.76 for coverage <5%; -3.27, 95%CI: -4.70, -1.84 for coverage 5%-10%; -0.60, 95%CI: -2.03, 0.83 for coverage ≥30%; COVID-y2: -2.74, 95%CI: -3.62, -1.87 for coverage <5%, -2.95, 95%CI: -3.98, -1.92 for coverage 5%-10%; -2.08, 95%CI: -3.28, -0.88 for coverage ≥30%). Findings support the consideration of nature exposure to improve people's mental wellbeing and resilience when designing lockdown measures in response to future public health emergencies.

Health and housing consequences of climate-related disasters: a matched case-control study using population-based longitudinal data in Australia

BACKGROUND

Understanding the role of how people are housed in reducing the long-term health and housing effects of climate-related disasters is crucial given our changing climate. We examine long-term health and housing trajectories and health effects of climate-related disasters in relation to housing vulnerabilities over a decade.

METHODS

We conducted a matched case-control study using longitudinal population-based data from the Household, Income and Labour Dynamics in Australia survey. We included data from people whose homes had been damaged by climate-related disasters (eg, flood, bushfire, or cyclone) between 2009 and 2019 and matched control cohorts with similar sociodemographic profiles who had not been exposed to disaster-related home damage during this period. We included data from de-identified individuals with at least 1 year of data before disaster and 3 years after disaster. One-to-one nearest neighbour matching was performed on the basis of demographic, socioeconomic, housing, health, neighbourhood, location, and climate characteristics 1 year before disaster. Conditional fixed-effects models for matched case-control groups were used to assess health trajectories, using eight quality-of-life domains on mental, emotional, social, and physical wellbeing, and housing trajectories, using three housing aspects of cost (ie, housing affordability and fuel poverty), security (ie, residential stability and tenure security), and condition (ie, housing quality and suitability).

FINDINGS

Exposure to home damage from climate-related disasters had significant negative effects on people's health and wellbeing at disaster year (difference between exposure and control groups in mental health score was -2·03, 95% CI -3·28 to -0·78; in social functioning score was -3·95, -5·57 to -2·33; and in emotional wellbeing score was -4·62, -7·06 to -2·18), with some effects lasting for 1-2 years after disaster. These effects were more severe for people who had housing affordability stress or were living in poor quality housing before the disaster. People in the exposure group had a slight increase in housing and fuel payment arrears following disasters. Homeowners had increased housing affordability stress (1 year after disaster: 0·29, 95% CI 0·02 to 0·57; 2 years after disaster: 0·25, 0·01 to 0·50), renters had a higher prevalence of acute residential instability (disaster year: 0·27, 0·08 to 0·47), and people who were exposed to disaster-related home damage had a higher prevalence of forced moves than did the control group (disaster year: 0·29, 0·14 to 0·45).

INTERPRETATION

Findings support the need for recovery planning and resilience building to consider housing affordability, tenure security, and housing condition. Interventions might require divergent strategies for populations in different precarious housing circumstances, and policies should target long-term housing support services for highly vulnerable groups.

FUNDING

The National Health and Medical Research Council Centre of Research Excellence in Healthy Housing, University of Melbourne Affordable Housing Hallmark Research Initiative Seed Funding, Australian Research Council's Centre of Excellence for Children and Families over the Life Course, and Lord Mayor's Charitable Foundation.

Vulnerability and recovery: Long-term mental and physical health trajectories following climate-related disasters

Extreme weather and climate-related disaster events are associated with a range of adverse health outcomes. People are not equally vulnerable to the adversity, experiencing varied patterns of long-term health trajectories in recovery depending on their vulnerabilities, capacities, and resiliencies. This study aims to identify latent mental and physical health trajectories and their associations with person- and place-based pre-disaster predictors. Using an Australian, population-based, longitudinal dataset spanning 2009-19, group-based multi-trajectory modelling was applied to identify the distinct mental, social, emotional, and physical health trajectories of people who had experienced damage to their home following a climate-related disaster event. Multinomial logistic regression was used to assess a series of social vulnerability predictors (demographic, socioeconomic, housing, health, neighbourhood, and geographical) of health patterns. We identified three distinct health trajectories. Most individuals experienced small or minimal health impacts at the time of the disaster year followed by a fast recovery. However, one-fifth of the exposed population were severely affected during and post disaster. This cohort had the worst mental and physical health prior to the disaster and experienced the largest decreases in mental and physical health and the lowest recoveries. Pre-existing mental and physical conditions were the most substantial risk factors, increasing the probability of experiencing high impact and slow recovery by 61% for mental health and 51% for physical health. In addition, vulnerability in the form of housing affordability stress, lower household income, and lack of community attachment, participation and safety were also significant independent risk factors for ongoing post-disaster health problems. Critically, people's mental and physical health recovery is dependent on pre-disaster vulnerabilities in health, resource access, and capacities. These findings could assist policymakers and health practitioners to more effectively target people most at risk and design prevention and response strategies to prevent the exacerbation of poor health and wellbeing.

Environmental Noise Exposure and Mental Health: Evidence From a Population-Based Longitudinal Study

INTRODUCTION

Exposure to environmental noise from within homes has been associated with poor mental health. Existing evidence rests on cross-sectional studies prone to residual confounding, reverse causation, and small sample sizes, failing to adequately consider the causal nature of this relationship. Furthermore, few studies have examined the sociodemographic distribution of noise exposure at a country level.

METHODS

The study, conducted in 2021, examined the impact of environmental noise from road traffic, airplanes, trains, and industry on mental health and psychological distress as reported by 31,387 respondents using a 19-year longitudinal data set in Australia (2001‒2019). To improve the capacity to make causal inference and reduce bias from measurement error, reverse causation, and unobserved confounders, analyses used instrumental variables, fixed-effects models, and an aggregated area-level measure of noise exposure. Utilizing the large-scale national data set, sociospatial distributions of noise exposure were described.

RESULTS

Private and public rental tenants, lone parents, residents of socioeconomically disadvantaged areas, and those with long-term health conditions were more likely to report residential noise exposure. This exposure to noise was consistently associated with poorer mental health (self-reported noise: β= -0.58; 95% CI= -0.76, -0.39; area-level noise: β= -0.43; 95% CI= -0.61, -0.26), with the relationship strongest for traffic noise (β= -0.79; 95% CI= -1.07, -0.51). Notably, when noise exposure decreased over time, there was an increase in mental health (β= 0.43; 95% CI= 0.14, 0.72).

CONCLUSIONS

The study provides strong evidence of a negative mental health effect of perceived residential noise, and the results have implications for healthy home design and urban planning. These findings should be validated with further studies that measure noise intensity and housing quality.

Evidence to guide ethical decision-making in the management of older people living in squalor: a narrative review

Older people living in squalor present healthcare providers with a set of complex issues because squalor occurs alongside a variety of medical and psychiatric conditions, and older people living in squalor frequently decline intervention. To synthesise empirical evidence on squalor to inform ethical decision‐making in the management of squalor using the bioethical framework of principlism. A systematic literature search was conducted using Medline, Embase, PsycINFO and CINAHL databases for empirical research on squalor in older people. Given the limited evidence base to date, an interpretive approach to synthesis was used. Sixty‐seven articles that met the inclusion criteria were included in the review. Our synthesis of the research evidence indicates that: (i) older people living in squalor have a high prevalence of frontal executive dysfunction, medical comorbidities and premature deaths; (ii) interventions are complex and require interagency involvement, with further evaluations needed to determine the effectiveness and potential harm of interventions; and (iii) older people living in squalor utilise more medical and social resources, and may negatively impact others around them. These results suggest that autonomous decision‐making capacity should be determined rather than assumed. The harm associated with squalid living for the older person, and for others around them, means a non‐interventional approach is likely to contravene the principles of non‐maleficence, beneficence and justice. Adequate assessment of decision‐making capacity is of particular importance. To be ethical, any intervention undertaken must balance benefits, harms, resource utilisation and impact on others.

Housing and health: an updated glossary

Recent crises have underscored the importance that housing has in sustaining good health and, equally, its potential to harm health. Considering this and building on Howden-Chapman's early glossary of housing and health and the WHO Housing and Health Guidelines, this paper introduces a range of housing and health-related terms, reflecting almost 20 years of development in the field. It defines key concepts currently used in research, policy and practice to describe housing in relation to health and health inequalities. Definitions are organised by three overarching aspects of housing: affordability (including housing affordability stress (HAS) and fuel poverty), suitability (including condition, accessibility and sustainable housing) and security (including precarious housing and homelessness). Each of these inter-related aspects of housing can be either protective of, or detrimental to, health. This glossary broadens our understanding of the relationship between housing and health to further promote interdisciplinarity and strengthen the nexus between these fields.

Estimating cardiovascular health gains from eradicating indoor cold in Australia

BACKGROUND

Exposure to cold indoor temperature (< 18 degrees Celsius) increases cardiovascular disease (CVD) risk and has been identified by the WHO as a source of unhealthy housing. While warming homes has the potential to reduce CVD risk, the reduction in disease burden is not known. We simulated the population health gains from reduced CVD burden if the temperature in all Australian cold homes was permanently raised from their assumed average temperature of 16 degrees Celsius to 20 degrees Celsius.

METHODS

The health effect of eradicating cold housing through reductions in CVD was simulated using proportional multistate lifetable model. The model sourced CVD burden and epidemiological data from Australian and Global Burden of Disease studies. The prevalence of cold housing in Australia was estimated from the Australian Housing Conditions Survey. The effect of cold indoor temperature on blood pressure (and in turn stroke and coronary heart disease) was estimated from published research.

RESULTS

Eradication of exposure to indoor cold could achieve a gain of undiscounted one and a half weeks of additional health life per person alive in 2016 (base-year) in cold housing through CVD alone. This equates to 0.447 (uncertainty interval: 0.064, 1.34; 3% discount rate) HALYs per 1,000 persons over remainder of their lives through CVD reduction. Eight percent of the total health gains are achievable between 2016 and 2035. Although seemingly modest, the gains outperform currently recommended CVD interventions including persistent dietary advice for adults 5-9% 5 yr CVD risk (0.017 per 1000 people, UI: 0.01, 0.027) and persistent lifestyle program for adults 5-9% 5 yr CVD risk (0.024, UI: 0.01, 0.027).

CONCLUSION

Cardiovascular health gains alone achievable through eradication of cold housing are comparable with real-life lifestyle and dietary interventions. The potential health gains are even greater given cold housing eradication will also improve respiratory and mental health in addition to cardiovascular disease.

Impact of COVID-19 shocks, precarity and mediating resources on the mental health of residents of share housing in Victoria, Australia: an analysis of data from a two-wave survey

OBJECTIVES

COVID-19 lockdown measures have challenged people's mental health, especially among economically vulnerable households. The objective of this study was to investigate the impact of exposure to COVID-19 shocks (defined as job loss, living cost pressures and changing housing conditions throughout the lockdown period) and double precarity (defined as precarity in housing and employment) on mental health outcomes for members of share households as well as the mediating effects of a range of resources.

DESIGN

We conducted a two-wave survey of occupants of share housing in June and October 2020 during a prolonged period of population lockdown. Research design involved fixed effects ordered logit regression models to assess the mental health consequences of baseline precarity and COVID-related shocks.

SETTING

Victoria, Australia.

PARTICIPANTS

We surveyed 293 occupants of share houses (mean age 34 SD 11.5, 56% female). Members of share houses (where individuals are unrelated adults and not in a romantic relationship) are more likely to be young, casually employed, visa-holders and low-income.

OUTCOME MEASURES

We measured household composition, housing and employment precarity, access to government support, household crowding, social networks and COVID-19 shocks. We used a self-reported measure of mental health.

RESULTS

Those exposed to COVID-19 shocks reported a 2.7 times higher odds of mental health deterioration (OR 2.7, 95% CI 1.53 to 4.85). People exposed to double precarity (precarity in both housing and employment) reported 2.4 times higher odds of mental health deterioration (OR 2.4, 95% CI 0.99 to 5.69). Housing inadequacy and lack of access to sufficient government payments explained 14.7% and 7% of the total effect of double precarity on mental health, respectively.

CONCLUSIONS

Results indicate that residents of group households characterised by pre-existing precarity were vulnerable to negative mental health effects during lockdown. Access to sufficient government payments and adequate housing buffered this negative effect.

An Australian rental housing conditions research infrastructure

Each year the proportion of Australians who rent their home increases and, for the first time in generations, there are now as many renters as outright homeowners. Researchers and policy makers, however, know very little about housing conditions within Australia’s rental housing sector due to a lack of systematic, reliable data. In 2020, a collaboration of Australian universities commissioned a survey of tenant households to build a data infrastructure on the household and demographic characteristics, housing quality and conditions in the Australian rental sector. This data infrastructure was designed to be national (representative across all Australian States and Territories), and balanced across key population characteristics. The resultant Australian Rental Housing Conditions Dataset (ARHCD) is a publicly available data infrastructure for researchers and policy makers, providing a basis for national and international research.

Measurement(s)	social survey
Technology Type(s)	CATI and online questionnaire
Sample Characteristic - Organism	Homo sapiens
Sample Characteristic - Environment	housing
Sample Characteristic - Location	Australia

Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.14842914

How much of the effect of disability acquisition on mental health is mediated through employment and income? A causal mediation analysis quantifying interventional indirect effects using data from four waves of an Australian cohort study

OBJECTIVES

There is evidence that disability acquisition causes a decline in mental health, but few studies have examined the causal mechanisms through which the effect operates. This study used a novel approach to mediation analysis to quantify interventional indirect effects (IIEs) through employment and income.

DESIGN AND SETTING

We used four waves of longitudinal data (2011-2014) from the Household, Income and Labour Dynamics in Australia Survey, a nationally representative survey of Australian households.

PARTICIPANTS

Working aged individuals who acquired a disability (n=233) were compared with those who remained disability-free in all four waves (n=5419).

PRIMARY OUTCOME MEASURE

Self-reported mental health was measured using the Mental Health Inventory subscale of the Short Form 36 general health questionnaire, which measures symptoms of depression, anxiety and psychological well-being.

STATISTICAL ANALYSIS

We conducted a causal mediation analysis quantifying IIEs of disability acquisition on mental health operating through two distinct mediators: employment status and income. We used multiple imputation with 50 imputed datasets to account for missing data.

RESULTS

The total causal effect of disability acquisition on mental health was estimated to be a 4.8-point decline in mental health score (estimated mean difference: -4.8, 95% CI -7.0 to -2.7). The IIE through employment was estimated to be a 0.5-point difference (-0.5, 95% CI -1.0 to 0.0), accounting for 10.6% of the total effect, whereas there was no evidence that income explained any of the effects.

CONCLUSIONS

This study estimated that disability-related mental health inequalities could be reduced by 10.6% if employment rates were the same for people with disability as those without disability. The results suggest that employment is implicated in the relationship between disability acquisition and mental health and that more research is needed to understand the influence of other aspects of employment and other socioeconomic characteristics.

Australia's Disability Employment Services Program: Participant Perspectives on Factors Influencing Access to Work

Disability employment programs play a key role in supporting people with disability to overcome barriers to finding and maintaining work. Despite significant investment, ongoing reforms to Australia's Disability Employment Services (DES) are yet to lead to improved outcomes. This paper presents findings from the Improving Disability Employment Study (IDES): a two-wave survey of 197 DES participants that aims to understand their perspectives on factors that influence access to paid work. Analysis of employment status by type of barrier indicates many respondents experience multiple barriers across vocational (lack of qualifications), non-vocational (inaccessible transport) and structural (limited availability of jobs, insufficient resourcing) domains. The odds of gaining work decreased as the number of barriers across all domains increased with each unit of barrier reported (OR 1.22, 95% CI 1.07, 1.38). Unemployed respondents wanted more support from employment programs to navigate the welfare system and suggest suitable work, whereas employed respondents wanted support to maintain work, indicating the need to better tailor service provision according to the needs of job-seekers. Combined with our findings from the participant perspective, improving understanding of these relationships through in-depth analysis and reporting of DES program data would provide better evidence to support current DES reform and improve models of service delivery.

Mapping home internet activity during COVID-19 lockdown to identify occupation related inequalities

During the COVID-19 pandemic, evidence has accumulated that movement restrictions enacted to combat virus spread produce disparate consequences along socioeconomic lines. We investigate the hypothesis that people engaged in financially secure employment are better able to adhere to mobility restrictions, due to occupational factors that link the capacity for flexible work arrangements to income security. We use high-resolution spatial data on household internet traffic as a surrogate for adaptation to home-based work, together with the geographical clustering of occupation types, to investigate the relationship between occupational factors and increased internet traffic during work hours under lockdown in two Australian cities. By testing our hypothesis based on the observed trends, and exploring demographic factors associated with divergences from our hypothesis, we are left with a picture of unequal impact dominated by two major influences: the types of occupations in which people are engaged, and the composition of households and families. During lockdown, increased internet traffic was correlated with income security and, when school activity was conducted remotely, to the proportion of families with children. Our findings suggest that response planning and provision of social and economic support for residents within lockdown areas should explicitly account for income security and household structure. Overall, the results we present contribute to the emerging picture of the impacts of COVID-19 on human behaviour, and will help policy makers to understand the balance between public health and social impact in making decisions about mitigation policies.

1366Environmental noise exposure and mental health: an analysis of a longitudinal survey of Australian households

Background

Persistent exposure to environmental noise in people’s homes has been associated with cardiovascular disease and poor mental health. Many studies conducted on noise and health are based on observational studies and the extent to which findings reflect residual confounding are not known.

Methods

Using the Household, Income and Labour Dynamics survey in Australia, we examine the impact of environmental noise (traffic, airplanes, train, industry) on self-reported mental health measured by the Short Form 36 Health Survey. Fixed-effects longitudinal regression analyses are used to account for differences between people over time, reducing confounding from time-invariant factors and reporting bias. Time-varying factors were adjusted including age, education, equivalised income, employment, household structure, chronic condition, government payment status and tenure type.

Results

Results show a significant decrease in average mental health as the level of noise increased. Exposure to loud traffic noise ‘fairly commonly’ or ‘very commonly’ negatively impacted mental health (-1.18; 95%CI -1.56, -0.81 and -1.33; 95%CI -1.77, -0.89) and exposure to noise from airplanes, trains or industry ‘fairly commonly’ or ‘very commonly’ negatively impacted mental health (-1.57; 95%CI -1.88, -1.27 and -1.48; 95%CI -1.89, -1.08).

Conclusions

This provides robust evidence of short-run mental health effects of noise exposure within people’s homes. More research could be done to explore this over a longer-time frame.

Key messages

With increasing numbers of people living in urban areas, reducing environmental noise near people’s homes or improving the capacity of homes to reduce external sources of noise (e.g. double glazing) may have public health benefit.

902Effect modification by homeownership in the relationship between household income and child oral health

Background

Poor oral health among children is socially patterned and poorly understood. To optimise interventions aimed at reducing the persistent socioeconomic gap in health, we need to understand its shaping mechanisms. We examined if homeownership modifies the widely recognised association between household income and child oral health.

Methods

Data were analysed on 3,344 children from the Longitudinal Study of Australian Children. Multivariable regression models tested associations between tertiles of household income and dental decay and tooth loss. Effect modification by homeownership was tested on both additive and multiplicative scales. Models were adjusted for demographic variables, area of residence and family characteristics.

Results

For dental decay and tooth loss, children in households in the lower tertiles of income had worse oral health than children in the highest. Additive interaction was weakly supported in our models. The relative effect of income on oral health was greater for homeowners than renters for dental decay (medium household income 0.65 (95%CI: 0.44; 0.98) and low household income 0.82 (95%CI: 0.58; 1.15)) and tooth loss (medium household income 0.25 (95%CI: 0.09; 0.68) and low household income 0.41 (95%CI: 0.17; 0.97)).

Conclusions

Low-income children have poorer oral health outcomes. Although children of homeowners have better oral health than children of renters, income inequality is higher among the homeowner’s group. Current rent assistance programs for low-income families in Australia may minimise income-related inequalities on a relative scale.

Key messages

Our findings shed light on the potential of equalising policies in reducing income-related oral health inequalities.

1443A causal mediation analysis of the effect of disability on mental health mediated by employment

Background

There is evidence that disability acquisition causes a decline in mental health, but few studies have examined the causal mechanisms through which the effect operates. This study used a novel approach to mediation analysis to quantify interventional indirect effects through employment and income.

Methods

We used four waves of longitudinal data to compare self-reported mental health between working aged individuals who acquired a disability (n = 233) and those who remained disability-free (n = 5419). We conducted a causal mediation analysis quantifying interventional indirect effects of disability acquisition on mental health operating through two distinct mediators: employment status and income. We used multiple imputation with 50 imputed datasets to account for missing data.

Results

The total causal effect of disability acquisition on mental health was estimated to be a 4.8-point decline in mental health score (estimated mean difference: -4.8, 95% CI -7.0, -2.7). The interventional indirect effect through employment was estimated to be a 0.5-point difference (-0.5, 95% CI -1.0, 0.0), accounting for 10.6% of the total effect, whereas there was no evidence that income explained any of the effect.

Conclusion

This study estimated that disability-related mental health inequalities could be reduced by 10.6% if employment rates were the same for people with disabilities as those without. The results highlight the need to implement measures to enable people with disabilities to remain in employment and improve employment and vocational training opportunities for people who acquire a disability.

989Relationship between housing tenure and cigarette smoking among adolescents – A population-based study

Background

Cigarette smoking leads to significant morbidity and pre-mature mortality. We examined the relationship between housing tenure at ages 15, 16, 17 and 18 and smoking five years later using data from a well-established cohort study.

Methods

We analysed the data on 15-18-year-old adolescents (n = 2305) from the Household Income and Labour Dynamics in Australia (HILDA) survey. We applied augmented inverse probability treatment weights to maximise exchangeability between those in social housing and homeowners, and private renters. By estimating potential outcomes for the exposed and unexposed, we compared risk of smoking five years later on both absolute and relative scale. Baseline covariates included household income, age at study entry, sex, family type, smoking at baseline and highest household education.

Results

Adolescents in social housing had an increased risk of current smoking five years later (average treatment effect (ATE): 0.24, 95% CI: 0.02, 0.47) than homeowners. On the relative scale those in social housing had 2.23 times (95% CI: 1.08, 3.39) higher risk of being a smoker than homeowners. Those in social housing also had an increased risk of being a smoker (ATE: 0.14, 95%CI: 0.04, 0.25) than private renters. On the relative scale we estimated that those in social housing had 1.46 times (95% CI: 1.09, 1.83) higher risk of smoking than private renters.

Conclusions

Adolescents in social housing have a higher risk of smoking than those living in owned or private rented homes.

Key messages

Tobacco control efforts must target adolescent in social housing for reducing inequalities in cigarette smoking.

1444Housing disadvantage in childhood and health: A systematic review

Background

Housing has been recognised as one of the important determinants of health outcomes. However, little is known of the contribution of these pathways to children’s health and wellbeing and their pattern of health throughout life. This review aims to provide a synthesis of longitudinal studies linking experiences of disadvantaged housing in childhood to health outcomes.

Methods

A literature search was performed on four databases including Medline, EMBASE, PsycINFO, and Web of Science from 2000 to 2020. Peer-reviewed longitudinal studies assessing the association between housing disadvantage in childhood and subsequent physical and mental health were included. The methodological quality of selected studies was appraised using the ROBINS-I tool. A narrative synthesis was developed due to study heterogeneity.

Results

Forty-five cohort studies were included, and no randomised controlled trial met the inclusion criteria. The majority of the studies was evaluated to have a moderate risk of bias. Across the studies, while many relationships remained mixed, consistent evidence of detrimental impact was identified between: poor housing conditions and mortality; inadequate heating and respiratory illness; frequent residential moves and psychiatric mortality and morbidity. Little evidence is found between overcrowding in childhood and health outcomes.

Conclusions

Evidence from longitudinal studies indicates that poor housing experience in childhood may impact health later in life.

Key messages

The findings stressed housing as a key social determinant of child health, and interventions designed to mitigate housing disadvantage may have significant health gains across the life span

1313Is private rental instability bad for mental health?

Background

People in the private rental sector move more than people in other tenures. Yet we know little about the consequences for health of this instability. We are the first to use a nationally representative longitudinal survey of Australians (2000-2018) to causally examine mental health effects of residential instability for a low-income working-aged cohort of private renters.

Methods

Mental health was measured using the SF-36 (MH) and Kessler Psychological Distress scale (K10). We examined effects of 1) cumulative time spent in private rental compared with other sectors (homeowner or social housing), 2) total numbers of transitions, and 3) average numbers of transitions within 5 years, using marginal structural models to account for complex confounding of tenure, socio-economic position, and mental health over time.

Results

The mental health of private renters was similar to homeowners at initial occupancy but became worse after one to five years. The more moves private renters made, the worse their mental health, with people who had &gt;five moves in total reporting a -3.77-point (95%CI -6.79; -0.75) difference on MH and -3.84-point difference (95%CI -7.61; -0.07) on K10 (rescaled). If numbers of moves were small, the mental health of private tenants was better than social tenants. When moves were frequent, however, their mental health scores became similar.

Conclusions

Residential instability negatively affects mental health. Frequent moves in private rental worsen tenants’ mental health compared to owners.

Key messages

Reducing housing instability in lower-income households in private rental with greater protection from forced moves will increase resident’s wellbeing.

The urban public realm and adolescent mental health and wellbeing: A systematic review

Adolescent mental health is becoming a critical concern. Mental illness rates are rising and many psychological disorders first present symptoms during teenage years. Studies consistently show associations between the built environment and mental health, including internalising mental health disorders in adults, but the evidence for adolescents is less robust and few studies attempt to isolate causality. This review examines the relationship between the urban public realm and adolescent mental health and wellbeing. Our search yielded 24 studies for inclusion. We undertook qualitative synthesis of 20 cross-sectional studies and conducted a separate quality analysis of four longitudinal studies. Greenspace and neighbourhood quality are associated with adolescent mental health and wellbeing although this may be due more to residual confounding, selection effects and same-source bias than evidence for a causal effect. Furthermore, the few longitudinal studies that seek to test causality remain prone to these biases. Overall, we find little evidence of an effect of the urban public realm on adolescent mental health and wellbeing, which, we argue, reflects the difficulty of researching complex pathways between environments and health and highlights a challenge to the field. To address this challenge, we propose a research agenda that prioritises more and better data drawn from diverse study designs, and more and better theories developed from diverse epistemologies.

Alcohol and tobacco consumption: What is the role of economic security?

AIMS

To better understand the longstanding inequalities concerning alcohol and tobacco use, we aimed to quantify the effect of household economic security on alcohol and tobacco consumption and expenditure.

DESIGN

Longitudinal analysis using data from the Household, Income and Labour Dynamics in Australia survey (2001-2018).

SETTING

Australia PARTICIPANTS: A nationally representative cohort of 24 134 adults aged 25-64 years (187 378 observations).

MEASUREMENTS

Tobacco and alcohol use (Yes/No), frequency of use of each per week, household expenditure on each per week, household weekly income (Consumer Price Index [CPI]-adjusted), employment security (based on conditions of employment) and housing affordability (housing costs relative to household income).

FINDINGS

At baseline, one-quarter of the sample used tobacco and 87% used alcohol. Annual increases in household income were associated with the increased use of both tobacco and alcohol for people in households in the lowest 40% of the national income distribution (OR = 1.13, 95% CI = 1.03-1.23 and OR = 1.12, 95% CI = 1.04-1.20, respectively) with no similar income effect observed for higher-income households. In relation to smoking, the odds of a resident's tobacco use increased when their household was unemployed (OR = 1.32, 95% CI = 1.07-1.62). In relation to alcohol, the odds of use decreased when households were insecurely employed or unemployed, or housing costs were unaffordable (OR = 0.87, 95% CI = 0.77-0.98, OR = 0.66, 95% CI = 0.55-0.80 and OR = 0.84, 95% CI = 0.75-0.93, respectively). This was also reflected in the reduced odds of risky drinking (defined in accordance with Australian guidelines) when housing became unaffordable or households became unemployed (OR = 0.90, 95% CI = 0.81-0.99; OR = 0.82, 95% CI = 0.69-0.98, respectively).

CONCLUSIONS

In Australia, smoking and drinking appear to exhibit different socio-behavioural characteristics and household unemployment appears to be a strong determinant of smoking.

Using machine learning to examine associations between the built environment and physical function: A feasibility study

Linking geospatial neighbourhood design characteristics to health and behavioural data from population-representative cohorts is limited by data availability and difficulty collecting information on environmental characteristics (e.g. greenery, building setbacks, dwelling structure). As an alternative, this study examined the feasibility of Generative Adversarial Networks (GANs) - machine learning - to measure neighbourhood design using 'street view' and aerial imagery to explore the relationship between the built environment and physical function. This study included 3102 adults aged 45 years and older clustered in 200 neighbourhoods in 2016 from the How Areas in Brisbane Influence Health and Activity (HABITAT) project in Brisbane, Australia. Exposure data were Google Street View and Google Maps images from within the 200 neighbourhoods, and outcome data were self-reported physical function using the PF-10 (a subset of the SF-36). Physical function scores were aggregated to the neighbourhood level, and the highest and lowest 20 neighbourhoods respectively were used in analysis. We found that the aerial imagery retrieved was unable to be used to adequately train the model, meaning that aerial imagery failed to produce meaningful results. Of the street view images, n = 56,330 images were downloaded and used to train the GAN model. Model outputs included augmented street view images between neighbourhoods classed as having high function and low function residents. The GAN model detected differences in neighbourhood design characteristics between neighbourhoods classed as high and low physical function at the aggregate level. Specifically, differences were identified in urban greenery (including tree heights) and dwelling structure (e.g. building height). This study provides important lessons for future work in this field, especially related to the uniqueness, diversity and amount of imagery required for successful applications of deep learning methods.

Reflection on modern methods: when worlds collide-prediction, machine learning and causal inference

Causal inference requires theory and prior knowledge to structure analyses, and is not usually thought of as an arena for the application of prediction modelling. However, contemporary causal inference methods, premised on counterfactual or potential outcomes approaches, often include processing steps before the final estimation step. The purposes of this paper are: (i) to overview the recent emergence of prediction underpinning steps in contemporary causal inference methods as a useful perspective on contemporary causal inference methods, and (ii) explore the role of machine learning (as one approach to 'best prediction') in causal inference. Causal inference methods covered include propensity scores, inverse probability of treatment weights (IPTWs), G computation and targeted maximum likelihood estimation (TMLE). Machine learning has been used more for propensity scores and TMLE, and there is potential for increased use in G computation and estimation of IPTWs.

Short-run effects of poverty on asthma, ear infections and health service use: analysis of the Longitudinal Study of Australian Children

BACKGROUND

Many studies have reported an inferred causal association of income poverty with physical health among children; but making causal inference is challenging due to multiple potential sources of systematic error. We quantified the short-run effect of changes in household poverty status on children's health (asthma and ear infections) and service use (visits to the doctor and parent-reported hospital admissions), using a national longitudinal study of Australian children, with particular attention to potential residual confounding and selection bias due to study attrition.

METHODS

We use four modelling approaches differing in their capacity to reduce residual confounding (generalized linear, random effects (RE), hybrid and fixed effects (FE) regression modelling) to model the effect of income poverty (<60% of median income) on health for 10 090 children surveyed every 2nd year since 2004. For each method, we simulate the potential impact of selection bias arising due to attrition related to children's health status.

RESULTS

Of the 10 090 children included, 20% were in families in poverty at survey baseline (2004). Across subsequent years, ∼25% experienced intermittent and <2% persistent poverty. No substantial associations between poverty and child physical health and service use were observed in the FE models least prone to residual confounding [odds ratio (OR) 0.94, 95% confidence interval (CI) 0.81-1.10 for wheeze], in contrast to RE models that were positive (consistent with previous studies). Selection bias causing null findings was unlikely.

CONCLUSIONS

While poverty has deleterious causal effects on children's socio-behavioural and educational outcomes, we find little evidence of a short-run causal effect of poverty on asthma, ear infections and health service use in Australia.

Home ownership, income and oral health of children in Australia-A population-based study

OBJECTIVE

Income inequalities in children's oral health have been well described. It is plausible that the security of tenure reflected by the ownership status of children's housing dynamically interacts with household income to shape these inequalities. We examined whether housing tenure modifies the known association between household income and oral health.

METHODS

Data were analysed on 3344 10- to 11-year-old children from the Longitudinal Study of Australian Children. Multivariable regression models tested associations between household income and dental caries and tooth loss due to caries. Effect modification by home ownership (yes/no) was tested on the additive and multiplicative scales. Models were adjusted for sex, Indigenous status, main language spoken at home, area of residence, main carer education and family arrangement.

RESULTS

Children in households in the low income group had worse oral health than children in the high group for caries and tooth loss. Models only weakly supported an additive interaction for tooth loss; that is, the relative excess risk due to interaction (RERI) for low household income was -0.903 (-2.38; 0.571) for tooth loss and -0.076 (-0.42; 0.271) for dental decay, although we note that the low proportion of children from low-income homeowning households (6%) reduces the power to detect interactions. Notably, our models suggest renters in both high- and low-income categories had the highest risk of tooth loss compared to owners (PR for high-income renters: 2.19 (95% CI: 1.25, 3.85); PR for low-income renters: 2.11 (95% CI: 1.42, 3.16)).

CONCLUSION

Our study confirms that children in low-income households have poorer oral health outcomes than their high-income counterparts. Our findings additionally suggest that children in rental households may fare the worst of all housing and income combinations considered. Improving the security of housing for families privately renting may have wider health benefits that currently acknowledged.

The relationship between income poverty and child hospitalisations in New Zealand: Evidence from longitudinal household panel data and Census data

Background

Very little high quality evidence exists on the causal relationship between income poverty and childhood health. We provide a comprehensive overview of the association between household income poverty and hospitalisations for children.

Methods

We used New Zealand’s Integrated Data Infrastructure (IDI) to link income poverty data from the Survey of Family, Income and Employment (SoFIE; n = 21,759 households) and the 2013 New Zealand Census (n = 523,302 households) to publicly funded hospital records of children aged 0–17 (SoFIE: n = 39,459; Census, n = 986,901). Poverty was defined as equivalised household income below 60% of the median income, calculated both before and after housing costs, and using both self-reported and tax-recorded income.

Results

Correlations for the association between income poverty and hospitalisation were small (ranging from 0.02 to 0.05) and risk ratios were less than 1.35 for all but the rarest outcome—oral health hospitalisation. Weak or absent associations were apparent across age groups, waves of data collection, cumulative effects, and for estimates generated from fixed effects models and random effect models adjusted for age and ethnicity. Alternative measures of deprivation (area-level deprivation and material deprivation) showed stronger associations with hospitalisations (risk ratios ranged from 1.27–2.55) than income-based poverty measures.

Conclusion

Income poverty is at best weakly associated with hospitalisation in childhood. Measures of deprivation may have a stronger association. Income measures alone may not be sufficient to capture the diversity of household economic circumstances when assessing the poverty-health relationship.

Autoantibody Biomarkers for Basal Ganglia Encephalitis in Sydenham Chorea and Pediatric Autoimmune Neuropsychiatric Disorder Associated With Streptococcal Infections

Movement, behavioral, and neuropsychiatric disorders in children have been linked to infections and a group of anti-neuronal autoantibodies, implying dopamine receptor-mediated encephalitis within the basal ganglia. The purpose of this study was to determine if anti-neuronal biomarkers, when used as a group, confirmed the acute disease in Sydenham chorea (SC) and pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS). IgG autoantibodies against four neuronal autoantigens (tubulin, lysoganglioside GM1, and dopamine receptors D1 and D2) were detected in SC sera (N=8), sera and/or cerebrospinal fluid (CSF) from two groups of PANDAS cases (N=25 first group and N=35 second group), sera from Tourette's syndrome (N=18), obsessive-compulsive disorder (N=25), attention deficit hyperactivity disorder (N=18), and healthy controls (N=28) by direct enzyme-linked immunosorbent assay (ELISA). IgG specific for neuronal autoantigens was significantly elevated during the acute symptomatic phase, and the activity of calcium/calmodulin-dependent protein kinase II (CaMKII) pathway was significantly elevated in human neuronal cells. Five assays confirmed the disease in SC and in two groups of children with PANDAS. In 35 acute onset PANDAS patients, 32 sera (91.4%) were positive for one or more of the anti-neuronal autoantibodies compared with 9 of 28 healthy controls (32.1%, p<0.0001). Importantly, CSF of 32 (91.4%) PANDAS patients had one or more detectable anti-neuronal autoantibody titers and CaMKII activation. Among healthy control subjects with elevated serum autoantibody titers for individual antigens, none (0%) were positively associated with elevated positive CaMKII activation, which was a striking contrast to the sera of PANDAS subjects, who had 76-89% positive association with elevated individual autoantibody titers and positive CaMKII activity. At 6 months follow-up, symptoms improved for more than 80% of PANDAS subjects, and serum autoantibody titers also significantly decreased. Results reported herein and previously published studies in our laboratory suggest the antibody biomarkers may be a useful adjunct to clinical diagnosis of SC, PANDAS, and related disorders and are the first known group of autoantibodies detecting dopamine receptor-mediated encephalitis in children.

Geographic variation in tobacco use in India: a population-based multilevel cross-sectional study

OBJECTIVE

This study aims to quantify the extent to which people's use of tobacco products varies by local areas (city ward and village) across India and the variation in this clustering by tobacco products.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

Data on 73 954 adults across 2547 city wards and villages were available for analysis from 30 states and 2 union territories in India.

PRIMARY AND SECONDARY OUTCOME MEASURES

We included as primary outcomes self-reported any tobacco use, current cigarette smoking, current bidi smoking, current smokeless tobacco use and a derived variable for dual use describing respondents who engaged in both smoking and smokeless tobacco use.

RESULTS

The median risk of an individual using tobacco was 1.64 times greater if a person hypothetically moved from an area of low to high risk of tobacco use (95% CI: 1.60 to 1.69). Area-level partitioning of variation differed by tobacco product used. Median ORs ranged from 1.77 for smokeless tobacco use to 2.53 for dual use.

CONCLUSIONS

Tobacco use is highly clustered geographically in India. To be effective in India, policy interventions should be directed to influence specific local contextual factors on adult tobacco use. Where people live in India influences their use of tobacco, and this association may be greater than has been observed in other settings. Tailoring tobacco control policies for local areas in India may, therefore, provide substantial public health benefits.

Do financial hardship and social support mediate the effect of unaffordable housing on mental health?

PURPOSE

Unaffordable housing has a negative impact on mental health; however, little is known about the causal pathways through which it transmits this effect. We examine the role of financial hardship and social support as mediators of this relationship.

METHODS

We identified households where housing costs changed from affordable to unaffordable across two waves of the Household, Income and Labour Dynamics in Australia (HILDA) Survey (2014-2015). The sequential causal mediation analysis was used to decompose the total effect of unaffordable housing on mental health into the portion attributable to financial hardship and social support [natural indirect effect (NIE)] and the portion not occurring through measured pathways [natural direct effect (NDE)]. Mental health was measured using the Mental Health Inventory (MHI) and Kessler psychological distress (KPD) scale. Baseline covariates included age, sex, household income, financial hardship, social support, marital status and employment status. Bootstrapping with 1000 replications was used to calculate 95% confidence intervals (CIs). Multiple imputations using chained equations were applied to account for missing data.

RESULTS

Unaffordable housing led to a change in mean mental health score on the MHI scale (- 1.3, 95% CI: - 2.1, - 0.6) and KPDS scale (0.9, 95% CI: 0.4, 1.4). Financial hardship accounted for 54% of the total effect on MHI scale and 53% on KPD scale. Collectively, financial hardship and social support explained 68% of the total effect on MHI scale and 67% on KPD scale, respectively.

CONCLUSIONS

In conclusion, the negative mental health effect of unaffordable housing is largely mediated through increased financial hardship.