The rise and fall of excess winter mortality in New Zealand from 1876 to 2020.

Excess winter mortality (EWM) has been used as a measure of how well populations and policy moderate the health effects of cold weather. We aimed to investigate long-term changes in the EWM of Aotearoa New Zealand (NZ), and potential drivers of change, and to test for structural breaks in trends. We calculated NZ EWM indices from 1876 (4,698 deaths) to 2020 (33,310 deaths), total and by age-group and sex, comparing deaths from June to September (the coldest months) to deaths from February to May and October to January. The mean age and sex-standardised EWM Index (EWMI) for the full study period, excluding 1918, was 1.22. However, mean EWMI increased from 1.20 for 1886 to 1917, to 1.34 for the 1920s, then reduced over time to 1.14 in the 2010s, with excess winter deaths averaging 4.5% of annual deaths (1,450 deaths per year) in the 2010s, compared to 7.9% in the 1920s. Children under 5 years transitioned from a summer to winter excess between 1886 and 1911. Otherwise, the EWMI age-distribution was J-shaped in all time periods. Structural break testing showed the 1918 influenza pandemic strain had a significant impact on trends in winter and non-winter mortality and winter excess for subsequent decades. It was not possible to attribute the post-1918 reduction in EWM to any single factor among improved living standards, reduced severe respiratory infections, or climate change.

Illustrating the impact of commercial determinants of health on the global COVID-19 pandemic: Thematic analysis of 16 country case studies.

Previous research on commercial determinants of health has primarily focused on their impact on non-communicable diseases. However, they also impact on infectious diseases and on the broader preconditions for health. We describe, through case studies in 16 countries, how commercial determinants of health were visible during the COVID-19 pandemic, and how they may have influenced national responses and health outcomes. We use a comparative qualitative case study design in selected low- middle- and high-income countries that performed differently in COVID-19 health outcomes, and for which we had country experts to lead local analysis. We created a data collection framework and developed detailed case studies, including extensive grey and peer-reviewed literature. Themes were identified and explored using iterative rapid literature reviews. We found evidence of the influence of commercial determinants of health in the spread of COVID-19. This occurred through working conditions that exacerbated spread, including precarious, low-paid employment, use of migrant workers, procurement practices that limited the availability of protective goods and services such as personal protective equipment, and commercial actors lobbying against public health measures. Commercial determinants also influenced health outcomes by influencing vaccine availability and the health system response to COVID-19. Our findings contribute to determining the appropriate role of governments in governing for health, wellbeing, and equity, and regulating and addressing negative commercial determinants of health.

Review of the Impact of Housing Quality on Inequalities in Health and Well-Being.

Housing quality is essential for population health and broader well-being. The World Health Organization Housing and health guidelines highlight interventions that protect occupants from cold and hot temperatures, injuries, and other hazards. The COVID-19 pandemic has emphasized the importance of ventilation standards. Housing standards are unevenly developed, implemented, and monitored globally, despite robust research demonstrating that retrofitting existing houses and constructing high-quality new ones can reduce respiratory, cardiovascular, and infectious diseases. Indigenous peoples, ethnic minorities, and people with low incomes face cumulative disadvantages that are exacerbated by poor-quality housing. These can be partially ameliorated by community-based programs to improve housing quality, particularly for children and older people, who are hospitalized more often for housing-related illnesses. There is renewed interest among policy makers and researchers in the health and well-being of people in public and subsidized housing, who are disproportionately disadvantaged by avoidable housing-related diseases and injuries. Improving the overall quality of new and existing housing and neighborhoods has multiple cobenefits, including reducing carbon emissions.

Indoor air quality, largely neglected and in urgent need of a refresh.

Nil.

Retrofitting home insulation reduces incidence and severity of chronic respiratory disease.

To assess whether retrofitting home insulation can reduce the risk of respiratory disease incidence and exacerbation, a retrospective cohort study was undertaken using linked data from a national intervention program. The study population was made up of 1 004 795 residents from 205 001 New Zealand houses that received an insulation subsidy though a national Energy Efficiency and Conservation Authority program. A difference-in-difference model compared changes in the number of prescriptions dispensed for respiratory illness post- insulation to a control population over the same timeframe. New prescribing of chronic respiratory disease medication at follow-up was used to compare incidence risk ratios between intervention and control groups. Chronic respiratory disease incidence was significantly lower in the intervention group at follow-up: odds ratio 0.90 (95% CI: 0.86-0.94). There was also a 4% reduction in medication dispensed for treating exacerbations of chronic respiratory disease symptoms in the intervention group compared with the control group: relative rate ratio (RRR) 0.96 (95% CI: 0.96-0.97). There was no change in medication dispensed to prevent symptoms of chronic respiratory disease RRR: 1,00 (95% CI: 0.99-1.00). These findings support home insulation interventions as a means of improving respiratory health outcomes.

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.

Residential mobility and potentially avoidable hospitalisations in a population-based cohort of New Zealand children.

BACKGROUND: Residential moves are common in early childhood and associations have been found between residential mobility and adverse child health and well-being outcomes. Although there are studies on potentially avoidable hospitalisations (PAH) in children, few have examined PAH in relation to residential mobility. Our aim, therefore, was to investigate residential mobility and PAH in a population-based cohort of New Zealand children. METHODS: Using a retrospective cohort design, we analysed data from the Integrated Data Infrastructure for a cohort of 314 283 children born since the start of 2004, who had at least one residential address recorded by 2 years of age. Residential mobility was derived from address data and PAH were determined from hospital discharge data. RESULTS: Half of the cohort children (52%) experienced at least one residential move by 2 years of age, and 22% experienced two or more moves. Fifteen per cent of the cohort experienced one or more PAH between 2 and 4 years of age. A linear association between residential mobility and PAH was found (relative risk (RR)=1.18, CI 1.17 to 1.19) and this remained robust when adjusting for several covariates. Sensitivity analyses for ambulatory care sensitive hospitalisations (ACSH) and PAH attributable to the housing/physical environment (PAH-HE) produced results very similar to those for PAH (ACSH: adjusted RR (aRR)=1.10, CI 1.09 to 1.11; PAH-HE: aRR=1.11, CI 1.10 to 1.12). CONCLUSION: This study found a linear association between higher residential mobility and an increased likelihood of PAH in young children. Avenues for further investigation are suggested.

Viruses associated with acute respiratory infection in a community-based cohort of healthy New Zealand children.

Acute respiratory infections (ARIs) are a major cause of morbidity among children. Respiratory viruses are commonly detected in both symptomatic and asymptomatic periods. The rates of infection and community epidemiology of respiratory viruses in healthy children needs further definition to assist interpretation of molecular diagnostic assays in this population. Children otherwise healthy aged 1 to 8 years were prospectively enrolled in the study during two consecutive winters, when ARIs peak in New Zealand. Parents completed a daily symptom diary for 8 weeks, during which time they collected a nasal swab from the child for each clinical ARI episode. A further nasal swab was collected by research staff during a clinic visit at the conclusion of the study. All samples were tested for 15 respiratory viruses commonly causing ARI using molecular multiplex polymerase chain reaction assays. There were 575 ARIs identified from 301 children completing the study, at a rate of 1.04 per child-month. Swabs collected during an ARI were positive for a respiratory virus in 76.8% (307 of 400), compared with 37.3% (79 of 212) of swabs collected during asymptomatic periods. The most common viruses detected were human rhinovirus, coronavirus, parainfluenza viruses, influenzavirus, respiratory syncytial virus, and human metapneumovirus. All of these were significantly more likely to be detected during ARIs than asymptomatic periods. Parent-administered surveillance is a useful mechanism for understanding infectious disease in healthy children in the community. Interpretation of molecular diagnostic assays for viruses must be informed by understanding of local rates of asymptomatic infection by such viruses.

'That house was a home': Qualitative evidence from New Zealand on the connections between rental housing eviction and poor health outcomes.

ISSUE ADDRESSED: Eviction, or a forced move from rental housing, is a common experience for New Zealand renters, yet we know very little about its effects. This research investigated how eviction affects people's lives and health. METHODS: We conducted semi-structured interviews with 27 people who had experienced eviction. We coded the transcripts and grouped them into themes using template analysis. RESULTS: Participant experienced grief at the loss of the home. Moving out and searching for a new home was highly stressful on participants and on their relationships. After being evicted, people became homeless, often staying with family and friends and lived in poor quality or unaffordable housing. They reported health issues as a result of these circumstances. CONCLUSIONS: Eviction harms health through causing stress, grief and a move to a risky living situation. Increasing the supply of housing and funding wide-ranging support services can help minimise the harm caused by eviction. SO WHAT?: Reducing the incidence and impact of eviction should be a priority for health promotion.

Home modifications to prevent home fall injuries in houses with Maori occupants (MHIPI): a randomised controlled trial.

BACKGROUND: As with many Indigenous populations internationally, Maori in New Zealand suffer health inequity. We aimed to assess the rate of fall injuries at home with and without home modifications in houses with Maori occupants. METHODS: We did a single-blind randomised controlled trial in the Wellington and Taranaki regions of New Zealand and enrolled owner-occupied households with at least one Maori occupant. Only households who stated they intended to live at that address for the subsequent 3 years were eligible for participation. We randomly assigned (1:1) households to either the intervention group, who received home modifications (handrails for outside steps and internal stairs, grab rails for bathrooms, outside lighting, repairs to window catches, high-visibility and slip-resistant edging for outside steps, fixing of lifted edges of carpets and mats, non-slip bath mats, and slip-resistant surfacing for outside areas such as decks) immediately, or the control group, who received the modifications 3 years later. Data on home injuries were obtained from the Accident Compensation Corporation and coded by study team members, who were masked to study group allocation. The primary outcome was the rate of medically treated fall injuries at home per household per year, analysed according to intention to treat. This Maori Home Injury Prevention Intervention (MHIPI) trial is now completed, and is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12613000148774. FINDINGS: Between Sept 3, 2013, and Oct 1, 2014, 824 households were assessed for eligibility and 254 were enrolled, of which 126 (50%) were assigned to the intervention group and 128 (50%) were assigned to the control group. After adjustment for previous falls and geographical region, there was an estimated 31% reduction in the rate of fall injuries at home per year exposed to the intervention compared with households in the control group (adjusted relative rate 0·69 [95% CI 0·47-1·00]). INTERPRETATION: Low-cost home modifications and repairs can be an effective means to reduce injury disparities. The high prevalence of modifiable safety issues in Maori homes merits considerable policy and community effort. FUNDING: Health Research Council of New Zealand.

Environmental burden of disease from unsafe and substandard housing, New Zealand, 2010-2017.

OBJECTIVE: To assess the burden of disease related to unsafe and substandard housing conditions in New Zealand from 2010 to 2017. METHODS: We focused on substandard housing conditions most relevant for New Zealand homes: crowding, cold, damp or mould, and injury hazards linked to falls. We estimated the population attributable fraction using existing estimates of the population exposed and exposure-response relationships of health disorders associated with each housing condition. We used government hospitalization data, no-fault accident insurance claims and mortality data to estimate the annual disease burden from the most severe cases, as well as the resulting costs to the public sector in New Zealand dollars (NZ$). Using value of a statistical life measures, we estimated the indirect cost of deaths. FINDINGS: We estimated that illnesses attributable to household crowding accounted for 806 nights in hospital annually; cold homes for 1834 hospital nights; and dampness and mould for 36 649 hospital nights. Home injury hazards resulted in 115 555 annual accident claims. We estimated that direct public sector costs attributable to these housing conditions were approximately NZ$ 141 million (100 million United States dollars, US$) annually. We also estimated a total of 229 deaths annually attributable to adverse housing and the costs to society from these deaths at around NZ$ 1 billion (US$ 715 million). CONCLUSION: Of the conditions assessed in this study, damp and mouldy housing accounted for a substantial proportion of the burden of disease in New Zealand. Improving people's living conditions could substantially reduce total hospitalization costs and potentially improve quality of life.

Residential mobility for a national cohort of New Zealand-born children by area socioeconomic deprivation level and ethnic group.

OBJECTIVES: The aims of this study are to describe area deprivation levels and changes that occur during residential moves involving New Zealand children from birth to their fourth birthday, and to assess whether these changes vary by ethnicity. DESIGN: Longitudinal administrative data. SETTING: Children born in New Zealand from 2004 to 2018. PARTICIPANTS: All (565 689) children born in New Zealand with at least one recorded residential move. OUTCOME MEASURES: A longitudinal data set was created containing lifetime address histories for our cohort. This was linked to the New Zealand Deprivation Index, a measure of small area deprivation. Counts of moves from each deprivation level to each other deprivation level were used to construct transition matrices. RESULTS: Children most commonly moved to an area with the same level of deprivation. This was especially pronounced in the most and least deprived areas. The number of moves observed also increased with deprivation. Maori and Pasifika children were less likely to move to, or remain in low-deprivation areas, and more likely to move to high-deprivation areas. They also had disproportionately high numbers of moves. CONCLUSION: While there was evidence of mobility between deprivation levels, the most common outcome of a move was no change in area deprivation. The most deprived areas had the highest number of moves. Maori and Pasifika children were over-represented in high-deprivation areas and under-represented in low-deprivation areas. They also moved more frequently than the overall population of 0 to 3 year olds.

Association between home insulation and hospital admission rates: retrospective cohort study using linked data from a national intervention programme.

OBJECTIVES: To investigate whether retrofitting insulation into homes can reduce cold associated hospital admission rates among residents and to identify whether the effect varies between different groups within the population and by type of insulation. DESIGN: A quasi-experimental retrospective cohort study using linked datasets to evaluate a national intervention programme. PARTICIPANTS: 994 317 residents of 204 405 houses who received an insulation subsidy through the Energy Efficiency and Conservation Authority Warm-up New Zealand: Heat Smart retrofit programme between July 2009 and June 2014. MAIN OUTCOME MEASURE: A difference-in-difference approach was used to compare the change in hospital admissions of the study population post-insulation with the change in hospital admissions of the control population that did not receive the intervention over the same two timeframes. Relative rate ratios were used to compare the two groups. RESULTS: 234 873 hospital admissions occurred during the study period. Hospital admission rates after the intervention increased in the intervention and control groups for all population categories and conditions with the exception of acute hospital admissions among Pacific Peoples (rate ratio 0.94, 95% confidence interval 0.90 to 0.98), asthma (0.92, 0.86 to 0.99), cardiovascular disease (0.90, 0.88 to 0.93), and ischaemic heart disease for adults older than 65 years (0.79, 0.74 to 0.84). Post-intervention increases were, however, significantly lower (11%) in the intervention group compared with the control group (relative rate ratio 0.89, 95% confidence interval 0.88 to 0.90), representing 9.26 (95% confidence interval 9.05 to 9.47) fewer hospital admissions per 1000 in the intervention population. Effects were more pronounced for respiratory disease (0.85, 0.81 to 0.90), asthma in all age groups (0.80, 0.70 to 0.90), and ischaemic heart disease in those older than 65 years (0.75, 0.66 to 0.83). CONCLUSION: This study showed that a national home insulation intervention was associated with reduced hospital admissions, supporting previous research, which found an improvement in self-reported health.

Structural Adjustment and Community Resilience: The Case of Postdisaster Housing Recovery After the Canterbury Earthquakes of 2010 and 2011.

BACKGROUND: This project is a case study of postdisaster housing recovery in Christchurch, New Zealand, after the Canterbury earthquakes of 2010 and 2011. AIMS: In this qualitative study, we analyzed the statutory framework governing the process of postdisaster housing recovery and its impact on local democracy. We also explored the role of communities and the third sector in housing and urban renewal. This aim was to contribute to the development of a critical theoretical understanding of community resilience as an inherently political concept. Community resilience is influenced by causal factors or generative mechanisms that affect the relations between people in a particular social context. METHOD: We completed a narrative synthesis of textual data from the thematic analysis of in-depth interviews with key informants, related policies, media, and fieldwork. RESULTS: A centralization of government authority over housing recovery resulted in an erosion of democracy and representative government at a local level. This centralization had major impacts on communities and their voice in the process of postdisaster housing recovery. Communities, however, never relented and worked tirelessly among themselves and with other social sectors to make a positive impact on postdisaster housing and urban recovery against difficult odds and stretched resources. This immense social capital and inspiring sense of community must be fostered and given the opportunity to democratically participate in the development of recovery policy as a key element of community resilience.

Well Homes Initiative: A Home-Based Intervention to Address Housing-Related Ill Health.

BACKGROUND: Six thousand children are hospitalized each year in New Zealand with housing sensitive conditions, and 86.2% of these children are rehospitalized during childhood. The Healthy Homes Initiative, set up by the Ministry of Health, and implemented in Wellington through Well Homes, carries out housing assessments and delivers a range of housing interventions. METHOD: Housing assessments were carried out by trained community workers. Philanthropic funding was received for the interventions through a local charitable trust. RESULTS: Well Homes saw 895 families. Mold in the home was the most commonly recorded area of poor housing quality, in 836 homes (93%). Partial or complete lack of insulation was also common, with 452 records (51%) having a documented need for further assessment and either an upgrade or full installation. Eighty-three percent of homes had insufficient sources of heating. A total of 5,537 interventions were delivered. Bedding, heaters, and draft stopping were delivered over 90% of the time. In contrast, insulation and carpets were only delivered 40% of the time. Interventions were least likely to be delivered in private rental housing. DISCUSSION: Targeted interventions using social partnerships can deliver housing improvements for relatively little health spending. Well Homes provides immediate and practical interventions, education, connection with social agencies, and advocacy for more substantial structural home improvements to help families keep their home warmer, drier, and healthier. This approach will be strengthened when combined with a new regulatory framework to raise the standards of private rental housing.

Renting Poorer Housing: Ecological Relationships Between Tenure, Dwelling Condition, and Income and Housing-Sensitive Hospitalizations in a Developed Country.

BACKGROUND: Previous research has shown two-way associations between rental tenure, poorer housing quality, and health outcomes, but little research has looked at relative housing contributions to health outcomes. AIMS: We investigated whether tenure and/or dwelling condition were associated with housing-sensitive hospitalizations and whether any association differed by income. METHOD: Using a data set of housing characteristics matched to hospitalization records, rental tenure data, and income quintiles, we modeled differences in housing-sensitive hospitalization rates by ecological-level tenure and housing condition, controlling for age-group and mean temperatures. RESULTS: There were clear associations between income, tenure, and house condition, and winter-associated hospitalization risk. In the adjusted model, the largest risk differences were associated with neighborhoods with low income (risk ratio [RR] = 1.48) and high rental tenure (RR = 1.41). There was a nonsignificant difference for housing condition (RR = 1.04). DISCUSSION: Rental tenure and poor housing condition were risks for housing-sensitive hospitalization, but the association with income was stronger. Higher income households may be better able to offset quality and tenure-related health risks. This research illustrates the inverse housing law: Those most vulnerable, with most need for good-quality housing, are least likely to have it. Income inequity is inbuilt in tenure, quality, and health burden relationships. CONCLUSION: These findings suggest that measures to address health inequities should include improvements to both tenure security and housing quality, particularly in low-income areas. However, policymakers aiming to reduce overall hospitalization rates should focus their efforts on reducing fuel poverty and improving the affordability of quality housing.

Commentary on Housing, Health, and Well-Being in Aotearoa/New Zealand.

Housing is poorly constructed for the New Zealand climate and is a major cause of poor health and premature mortality. Private rental housing is older and in poorer condition than public housing and owner-occupied housing. This special issue describes four different approaches to improving housing, which have implications for international housing, health, and well-being policies. The first approach looks at generating the evidence base for improving the quality of the rental sector; the second, the aftereffects of the Christchurch earthquake and the unprecedented role taken by the central government to override local government and community involvement in rebuilding housing and regenerating the city; the third, measuring the effectiveness of the remediation of public housing; and finally, community-based partnerships between community workers and academics to improve the housing of children who have been hospitalized for housing-sensitive hospitalizations.

Public Housing and Well-Being: Evaluation Frameworks to Influence Policy.

BACKGROUND: A robust evidence base is needed to develop sustainable cross-party solutions for public housing to promote well-being. The provision of public housing is politically contentious in New Zealand, as in many liberal democracies. Depending on the government, policies oscillate between encouraging sales of public housing stock and reducing investment and maintenance, and large-scale investment, provision, and regeneration of public housing. AIM: We aimed to develop frameworks to evaluate the impact of public housing regeneration on tenant well-being at the apartment, complex, and community levels, and to inform future policies. METHOD: Based on a systems approach and theory of change models, we developed a mixed methods quasi-experimental before-and-after outcomes evaluation frameworks, with control groups, for three public housing sites. This evaluation design had flexibility to accommodate real-world complexities, inherent in evaluating large-scale public health interventions, while maintaining scientific rigor to realize the full effects of interventions. RESULTS: Three evaluation frameworks for housing were developed. The evaluation at the apartment level confirmed proof of concept and viability of the framework and approach. This also showed that minor draught-stopping measures had a relatively big impact on indoor temperature and thermal comfort, which subsequently informed healthy housing standards. The complex and community-level evaluations are ongoing due to longer regeneration timeframes. CONCLUSION: Public housing is one of central government's larger social sector interventions, with Kainga Ora - Homes and Communities the largest Crown entity. Evaluating public housing policies is important to develop an evidence base to inform best practice, rational, decision-making policy for the public as well as the private sector.