A systematic review of associations between maternal exposures during pregnancy other than smoking and antenatal fetal measurements.

BACKGROUND: Reduced birth weight is associated with many maternal environmental exposures during pregnancy, but the gestational age at onset of this association is unknown. We have previously reported associations between maternal smoking and fetal size. OBJECTIVE: To report on our systematic review of the literature describing associations between antenatal size and growth and maternal exposures during pregnancy. DATA SOURCES: Electronic databases (OVID and EMBASE) and web sites for cohort studies were searched. Studies were eligible if they examined associations between maternal environmental exposures (including ambient air exposure, diet and alcohol) and antenatal fetal ultrasound measurements. The Navigation Guide was used to assess the strength of evidence. RESULTS: There were 451 abstracts identified and 36 papers were included of which maternal diet was the exposure of interest in 15, maternal ambient air exposure in 10, maternal alcohol in 3 and other exposures in 8. The first paper was published in 2006. Associations were present between exposures and fetal measurements in 18% of comparisons with second trimester measurements and in 46% of comparisons with third trimester measurements. In the third trimester, when an association was present, reduced head size was most commonly (58%) associated with current or previous maternal exposure, with reduced length being least commonly (32%) associated and reduced weight being intermediate (52%). In the third trimester, increased maternal nitrogen dioxide exposure was associated with reduced head size was associated with in all seven studies identified and reduced fetal weight in five out of six studies. CONCLUSION: There is sufficient evidence of toxicity in the context of maternal exposure to nitrogen dioxide and reduced third trimester fetal head size. There is currently insufficient evidence of toxicity with regard to maternal exposures to dietary factors, alcohol and environmental chemicals and reduced fetal size.

Neighbourhood tobacco supply and individual maternal smoking during pregnancy: a fixed-effects longitudinal analysis using routine data.

BACKGROUND: Tobacco policy is increasingly focusing on the 'tobacco endgame' which commits to eradicating tobacco use (prevalence below 5%) within the next two decades. Strategies for achieving the endgame are likely to include addressing the supply of tobacco products, yet current evidence to support this approach is primarily cross-sectional. METHODS: We use longitudinal smoking information from routine maternity records of all women who gave birth in Scotland between 2000 and 2015. We linked this data to the residential density of retailers selling tobacco products and the neighbourhood prevalence of smoking during pregnancy. In the analysis, individual mothers act as their own controls because we compare changes in their smoking behaviour between pregnancies to changes in exposure to tobacco retailing that arises from residential movement between pregnancies. RESULTS: Adjusted ORs showed an increased risk of being a smoker associated with increases in exposure to retailer density (OR 1.67, 95% CI 1.27 to 2.20). CONCLUSIONS: The results provide the strongest evidence to date of an association between the neighbourhood availability of tobacco and smoking, and the first to do so among pregnant women. These findings provide supportive evidence for interventions targeting the supply of tobacco products in achieving the endgame.

Health of Southern Tasmanian 4- to 6-year-old children in out-of-home care compared to peers.

AIM: To compare the health of 4- to 6-year-old children in out-of-home care (OOHC) in Southern Tasmania with their peers. METHODS: Demographic and health data collection and prospective health assessment of all 4- to 6-year olds in OOHC in Southern Tasmania on 30 August 2011 was undertaken. Data were compared to Tasmanian and/or Australian peers. RESULTS: A total of 109 of 129 children aged 4 to 6 years were included in the study. Time in OOHC was on average 38 (range 0-76) months. Premature birth (18%), low birthweight (20%) and congenital malformations (10%) were more common compared to peers. Antenatal exposure to illicit or abused substances (71%), alcohol (51%) and cigarettes (79%) were very high. Vertically acquired hepatitis C was diagnosed in 2% with 33% exposed. Immunisation completion was 78% compared to 92.9% of Tasmanian peers. Obesity (11% vs. 6% Tasmanian children), hearing impairment (7% vs. 1% Tasmanian children) and dental caries (61% vs. 45% Tasmanian children) were all higher than peers. Hospitalisation due to injury was more than twice that of Tasmanian peers (32.1 vs. 12.6 per 1000 per year). Developmental delay was 50% on screening. Emotional or behavioural difficulties were seen in 54%. CONCLUSIONS: Children in OOHC have high health needs. Comprehensive health assessments offer an opportunity to better identify and manage these needs. High hepatitis C exposure in utero was unexpected. This study highlights the need for comprehensive health screening assessments for all children in OOHC. OOHC clinic data can be helpful in planning broad interventions for children in OOHC.

Pregnancy outcome and ultraviolet radiation; A systematic review.

BACKGROUND: Season and vitamin D are indirect and direct correlates of ultraviolet (UV) radiation and are associated with pregnancy outcomes. Further to producing vitamin D, UV has positive effects on cardiovascular and immune health that may support a role for UV directly benefitting pregnancy. OBJECTIVES: To investigate the effects of UV exposure on pregnancy; specifically fetal growth, preterm birth and hypertensive complications. METHODS: We conducted a systematic review of Medline, EMBASE, DoPHER, Global Health, ProQuest Public Health, AustHealth Informit, SCOPUS and Google Scholar to identify 537 citations, 8 of which are included in this review. This review was registered on PROSPERO and a. narrative synthesis is presented following PRISMA guidance. RESULTS: All studies were observational and assessed at high risk of bias. Higher first trimester UV was associated with and improved fetal growth and increased hypertension in pregnancy. Interpretation is limited by study design and quality. Meta-analysis was precluded by the variety of outcomes and methods. DISCUSSION: The low number of studies and risk of bias limit the validity of any conclusions. Environmental health methodological issues are discussed with consideration given to design and analytical improvements to further address this reproductive environmental health question. CONCLUSIONS: The evidence for UV having benefits for pregnancy hypertension and fetal growth is limited by the methodological approaches utilized. Future epidemiological efforts should focus on improving the methods of modeling and linking widely available environmental data to reproductive health outcomes.

Living in stressful neighbourhoods during pregnancy: an observational study of crime rates and birth outcomes.

Background: Patterns of adverse birth outcomes vary spatially and there is evidence that this may relate to features of the physical environment such as air pollution. However, other social characteristics of the environment such as levels of crime are relatively understudied. This study examines the association between crime rates and birth weight and prematurity. Methods: Maternity inpatient data recorded at birth, including residential postcode, was linked to a representative 5% sample of Scottish Census data and small area crime rates from Scottish Police forces. Coefficients associated with crime were reported from crude and confounder adjusted models predicting low birth weight (< 2500 g), mean birthweight, small for gestational age and prematurity for all singleton live births. Results: Total crime rates were associated with strong and significant reductions in mean birth weight and increases in the risks of both a small for gestational age baby and premature birth. These effects, with the exception of prematurity, were robust to adjustment for individual characteristics including smoking, ethnicity and other socio-economic variables as well as area based confounders including air pollution. Mean birth weight was robust to additional adjustment for neighbourhood income deprivation. Conclusion: The level of crime in a mother's area of residence, which may be a proxy for the degree of threat felt and therefore stress experienced, appears to be an important determinant of the risk of adverse birth outcomes.

Place of work and residential exposure to ambient air pollution and birth outcomes in Scotland, using geographically fine pollution climate mapping estimates.

OBJECTIVES: A relationship between ambient air pollution and adverse birth outcomes has been found in a large number of studies that have mainly used a nearest monitor methodology. Recent research has suggested that the effect size may have been underestimated in these studies. This paper examines associations between birth outcomes and ambient levels of residential and workplace sulphur dioxide, particulates and Nitrogen Dioxide estimated using an alternative method - pollution climate mapping. METHODS: Risk of low birthweight and mean birthweight (for n=21,843 term births) and risk of preterm birth (for n=23,086 births) were modelled against small area annual mean ambient air pollution concentrations at work and residence location adjusting for potential confounding factors for singleton live births (1994-2008) across Scotland. RESULTS: Odds ratios of low birthweight of 1.02 (95% CI, 1.01-1.03) and 1.07 (95% CI, 1.01-1.12) with concentration increases of 1 µg/m(3) for NO2 and PM10 respectively. Raised but insignificant risks of very preterm birth were found with PM10 (relative risk ratio=1.08; 95% CI, 1.00 to 1.17 per 1 µg/m(3)) and NO2 (relative risk ratio=1.01; 95% CI, 1.00 to 1.03 per 1 µg/m(3)). An inverse association between mean birthweight and mean annual NO2(-1.24 g; 95% CI, -2.02 to -0.46 per 1 µg/m(3)) and PM10 (-5.67 g; 95% CI, -9.47 to -1.87 per 1 µg/m(3)). SO2 showed no significant associations. CONCLUSIONS: This study highlights the association between air pollution exposure and reduced newborn size at birth. Together with other recent work it also suggests that exposure estimation based on the nearest monitor method may have led to an under-estimation of the effect size of pollutants on birth outcomes.

What is the effect of unemployment on all-cause mortality? A cohort study using propensity score matching.

BACKGROUND: There is a strong association between unemployment and mortality, but whether this relationship is causal remains debated. This study utilizes population-level administrative data from Scotland within a propensity score framework to explore whether the association between unemployment and mortality may be causal. METHODS: The study examined a sample of working men and women aged 25-54 in 1991. Subsequent employment status in 2001 was observed (in work or unemployed) and the relative all-cause mortality risk of unemployment between 2001 and 2010 was estimated. To account for potential selection into unemployment of those in poor health, a propensity score matching approach was used. Matching variables were observed prior to unemployment and included health status up to the year of unemployment (hospital admissions and self-reported limiting long-term illness), as well as measures of socioeconomic position. RESULTS: Unemployment was associated with a significant all-cause mortality risk relative to employment for men (hazard ratio [HR] 1.85; 95% confidence interval [CI] 1.33-2.55). This effect was robust to controlling for prior health and sociodemographic characteristics. Effects for women were smaller and statistically insignificant (HR 1.51; 95% CI 0.68-3.37). CONCLUSION: For men, the findings support the notion that the often-observed association between unemployment and mortality may contain a significant causal component; although for women, there is less support for this conclusion. However, female employment status, as recorded in the census, is more complex than for men and may have served to underestimate any mortality effect of unemployment. Future work should examine this issue further.

A method for estimating wage, using standardised occupational classifications, for use in medical research in the place of self-reported income.

BACKGROUND: Income is predictive of many health outcomes and is therefore an important potential confounder to control for in studies. However it is often missing or poorly measured in epidemiological studies because of its complexity and sensitivity. This paper presents and validates an alternative approach to the survey collection of reported income through the estimation of a synthetic wage measure based on occupation. METHODS: A synthetic measure of weekly wage was calculated using a multilevel random effects model of wage predicted by a Standard Occupational Classification (SOC) fitted in data from the UK Labour Force Survey (years 2001-2010)a. The estimates were validated and tested by comparing them to reported income and then contrasting estimated and reported income's association with measures of health in the Scottish Health Survey (SHS) 2003 and wave one (2009) of the UK Household Longitudinal Study (UKHLS). RESULTS: The synthetic estimates provided independent and additional explanatory power within models containing other traditional proxies for socio-economic position such as social class and small area based measures of socio-economic position. The estimates behaved very similarly to 'real', reported measures of both household and individual income when modelling a measure of 'general health'. CONCLUSIONS: The findings suggest that occupation based synthetic estimates of wage are as effective in capturing the underlying relationship between income and health as survey reported income. The paper argues that the direct survey measurement of income in every study may not actually be necessary or indeed optimal.

Does cycle commuting reduce the risk of mental ill-health? An instrumental variable analysis using distance to nearest cycle path.

BACKGROUND: Previous studies have linked cycling with improved mental wellbeing but these studies tend to use cross-sectional survey data that have small sample sizes and self-reported health measures, and are potentially susceptible to omitted-variable bias and reverse causation. We use an instrumental variable approach and an objective measure of mental ill-health taken from linked administrative data to ask: 'Does cycle commuting reduce the risk of mental ill-health?' METHODS: Our study links data on commuting in Edinburgh and Glasgow from the Scottish population census with mental health prescriptions from the National Health Service Prescribing Information System records. We use road distance from home to nearest cycle path as an instrumental variable for cycle commuting. RESULTS: In total, 378 253 people aged 16-74 years living and working in the City of Edinburgh and Glasgow City council areas at the 2011 census were included in our study; 1.85% of commuters in Glasgow and 4.8% of commuters in Edinburgh cycled to work. Amongst cyclists, 9% had a prescription for mental health compared with 14% amongst non-cyclists. Using a bivariate probit model, we estimate a mean average reduction in prescriptions for antidepressants and/or anxiolytics in the 5 years following the census of -15.1% (95% CI: -15.3% to -15.0%) amongst cycle commuters compared with those who use any other mode to commute. CONCLUSIONS: This work suggests that cycle commuting is causally related to reduced mental ill-health and provides further evidence in support of the promotion of active travel to encourage commuters travelling shorter distances to shift to cycle commutes.

Improvement in rheumatic fever and rheumatic heart disease management and prevention using a health centre-based continuous quality improvement approach.

BACKGROUND: Rheumatic heart disease (RHD) remains a major health concern for Aboriginal Australians. A key component of RHD control is prevention of recurrent acute rheumatic fever (ARF) using long-term secondary prophylaxis with intramuscular benzathine penicillin (BPG). This is the most important and cost-effective step in RHD control. However, there are significant challenges to effective implementation of secondary prophylaxis programs. This project aimed to increase understanding and improve quality of RHD care through development and implementation of a continuous quality improvement (CQI) strategy. METHODS: We used a CQI strategy to promote implementation of national best-practice ARF/RHD management guidelines at primary health care level in Indigenous communities of the Northern Territory (NT), Australia, 2008-2010. Participatory action research methods were employed to identify system barriers to delivery of high quality care. This entailed facilitated discussion with primary care staff aided by a system assessment tool (SAT). Participants were encouraged to develop and implement strategies to overcome identified barriers, including better record-keeping, triage systems and strategies for patient follow-up. To assess performance, clinical records were audited at baseline, then annually for two years. Key performance indicators included proportion of people receiving adequate secondary prophylaxis (≥80% of scheduled 4-weekly penicillin injections) and quality of documentation. RESULTS: Six health centres participated, servicing approximately 154 people with ARF/RHD. Improvements occurred in indicators of service delivery including proportion of people receiving ≥40% of their scheduled BPG (increasing from 81/116 [70%] at baseline to 84/103 [82%] in year three, p = 0.04), proportion of people reviewed by a doctor within the past two years (112/154 [73%] and 134/156 [86%], p = 0.003), and proportion of people who received influenza vaccination (57/154 [37%] to 86/156 [55%], p = 0.001). However, the proportion receiving ≥80% of scheduled BPG did not change. Documentation in medical files improved: ARF episode documentation increased from 31/55 (56%) to 50/62 (81%) (p = 0.004), and RHD risk category documentation from 87/154 (56%) to 103/145 (76%) (p < 0.001). Large differences in performance were noted between health centres, reflected to some extent in SAT scores. CONCLUSIONS: A CQI process using a systems approach and participatory action research methodology can significantly improve delivery of ARF/RHD care.

Near-fatal and fatal asthma and air pollution: are we missing an opportunity to ask key questions?

There is an increasing body of evidence supporting the link between asthma attacks and air pollution in children. To our knowledge, there has only been one reported case of a fatal asthma attack in a child associated with air pollution and this was in the UK. This article considers why there is a lack of evidence on fatal/near-fatal asthma and air pollution. We also explore three challenges. First, fatal and near-fatal asthma events are rare and not yet well understood. Second, measuring and interpreting personal exposure to air pollution with sufficient temporal and spatial detail are challenging to interpret in the context of individual fatal or near-fatal asthma attacks. Third, current studies are not designed to answer the question of whether or to what extent air pollution is associated with fatal/near-fatal asthma attacks in children. Conclusive evidence is not yet available and systems of data collection for both air pollution and fatal and near-fatal asthma attacks should be enhanced to ensure risk can be determined and impact minimised.

Exploring the influence of local alcohol availability on drinking norms and practices: A qualitative scoping review.

INTRODUCTION: High alcohol availability is related to increased alcohol consumption and harms. Existing quantitative research provides potential explanations for this relationship but there is little understanding of how people experience local alcohol availability. This is the first review to synthesise qualitative research exploring the relationship between alcohol availability and other factors in local alcohol environments. METHODS: The scoping review includes qualitative studies exploring community-level alcohol availability and other factors, facilitating the purchase and consumption of alcohol. We included studies focusing on children and adolescents as well as adults. Study findings were brought together using thematic analysis and the socio-environmental context model, which explains how certain environments may facilitate drinking. RESULTS: The review includes 34 articles. The majority of studies were conducted since 2012. Most studies were conducted in the United Kingdom, Australia and South Africa. The physical availability of alcohol and proximity to local amenities and temporal aspects, like late night opening hours, may be linked to social factors, such as normalisation of drinking and permissive drinking environments. The review highlights the importance of social and cultural factors in shaping interactions with local alcohol environments. DISCUSSION AND CONCLUSION: This qualitative scoping review advances understanding of the pathways linking alcohol availability and alcohol harms by showing that availability, accessibility and visibility of alcohol may contribute towards permissive drinking environments. Further research is needed to better understand how people experience alcohol availability in their local environment and how this can inform alcohol control policies.

SARS-CoV-2 tests, confirmed infections and COVID-19-related hospital admissions in children and young people: birth cohort study.

BACKGROUND: There have been no population-based studies of SARS-CoV-2 testing, PCR-confirmed infections and COVID-19-related hospital admissions across the full paediatric age range. We examine the epidemiology of SARS-CoV-2 in children and young people (CYP) aged <23 years. METHODS: We used a birth cohort of all children born in Scotland since 1997, constructed via linkage between vital statistics, hospital records and SARS-CoV-2 surveillance data. We calculated risks of tests and PCR-confirmed infections per 1000 CYP-years between August and December 2020, and COVID-19-related hospital admissions per 100 000 CYP-years between February and December 2020. We used Poisson and Cox proportional hazards regression models to determine risk factors. RESULTS: Among the 1 226 855 CYP in the cohort, there were 378 402 tests (a rate of 770.8/1000 CYP-years (95% CI 768.4 to 773.3)), 19 005 PCR-confirmed infections (179.4/1000 CYP-years (176.9 to 182.0)) and 346 admissions (29.4/100 000 CYP-years (26.3 to 32.8)). Infants had the highest COVID-19-related admission rates. The presence of chronic conditions, particularly multiple types of conditions, was strongly associated with COVID-19-related admissions across all ages. Overall, 49% of admitted CYP had at least one chronic condition recorded. CONCLUSIONS: Infants and CYP with chronic conditions are at highest risk of admission with COVID-19. Half of admitted CYP had chronic conditions. Studies examining COVID-19 vaccine effectiveness among children with chronic conditions and whether maternal vaccine during pregnancy prevents COVID-19 admissions in infants are urgently needed.

GroundsWell: Community-engaged and data-informed systems transformation of Urban Green and Blue Space for population health - a new initiative.

Natural environments, such as parks, woodlands and lakes, have positive impacts on health and wellbeing. Urban Green and Blue Spaces (UGBS), and the activities that take place in them, can significantly influence the health outcomes of all communities, and reduce health inequalities. Improving access and quality of UGBS needs understanding of the range of systems (e.g. planning, transport, environment, community) in which UGBS are located. UGBS offers an ideal exemplar for testing systems innovations as it reflects place-based and whole society processes , with potential to reduce non-communicable disease (NCD) risk and associated social inequalities in health. UGBS can impact multiple behavioural and environmental aetiological pathways. However, the systems which desire, design, develop, and deliver UGBS are fragmented and siloed, with ineffective mechanisms for data generation, knowledge exchange and mobilisation. Further, UGBS need to be co-designed with and by those whose health could benefit most from them, so they are appropriate, accessible, valued and used well. This paper describes a major new prevention research programme and partnership, GroundsWell, which aims to transform UGBS-related systems by improving how we plan, design, evaluate and manage UGBS so that it benefits all communities, especially those who are in poorest health. We use a broad definition of health to include physical, mental, social wellbeing and quality of life. Our objectives are to transform systems so that UGBS are planned, developed, implemented, maintained and evaluated with our communities and data systems to enhance health and reduce inequalities. GroundsWell will use interdisciplinary, problem-solving approaches to accelerate and optimise community collaborations among citizens, users, implementers, policymakers and researchers to impact research, policy, practice and active citizenship. GroundsWell will be shaped and developed in three pioneer cities (Belfast, Edinburgh, Liverpool) and their regional contexts, with embedded translational mechanisms to ensure that outputs and impact have UK-wide and international application.

Higher Sun Exposure in the First Trimester Is Associated With Reduced Preterm Birth; A Scottish Population Cohort Study Using Linked Maternity and Meteorological Records.

Background: Preterm birth (birth at <37 weeks gestation) is the leading cause of death in children under 5-years-old, and prevention is a global public health issue. Seasonal patterns of preterm birth have been reported, but factors underlying this have been poorly described. Sun exposure is an important environmental variable that has risks and benefits for human health, but the effects of sun exposure on pregnancy duration and preterm birth are unknown. Objectives: To determine the association between available sun exposure and preterm birth. Methods: We performed a population-based data-linkage study of 556,376 singleton births (in 397,370 mothers) at or after 24 weeks gestation, in Scotland between 2000 and 2010. Maternity records were linked to available sun exposure from meteorological records, by postcode. Logistic regression analysis was used to explore the relationship between available sunshine and preterm birth at <37 weeks gestation. Exploratory analyses included a subgroup analysis of spontaneous and indicated preterm births and a sibling analysis in sib pairs discordant for preterm birth. Results: The rate of preterm birth was 6% (32,958/553,791 live births). Increased available sun exposure in the first trimester of pregnancy was associated with a reduced risk of preterm birth, with evidence of a dose-response. Compared with the lowest quartile of sun exposure, the highest quartile of sun exposure was associated with a reduced odds ratio (OR) of preterm birth of 0.90 (95% Confidence Interval (CI) 0.88-0.94 p < 0.01) on univariable analysis and OR of 0.91 (95% CI 0.87, 0.93 p < 0.01) after adjustment for second trimester sunlight exposure, parity, maternal age, smoking status, and deprivation category. No association was seen between preterm birth and second trimester available sun exposure or combined first and second trimester exposure. Similar patterns were seen on sibling analysis and within both the indicated and spontaneous preterm subgroups. Discussion: Available sun exposure in the first trimester of pregnancy is associated with a protective effect on preterm birth <37 weeks gestation. This opens up new mechanisms, and potential therapeutic pathways, for preterm birth prevention.

Antenatal Exposure to UV-B Radiation and Preeclampsia: A Retrospective Cohort Study.

Background Risk of preeclampsia varies by month of delivery. We tested whether this seasonal patterning may be mediated through maternal vitamin D concentration using antenatal exposure to UV-B radiation as an instrumental variable. Methods and Results Scottish maternity records were linked to antenatal UV-B exposure derived from satellites between 2000 and 2010. Logistic regression analyses were used to explore the association between UV-B and preeclampsia, adjusting for the potential confounding effects of month of conception, child's sex, gestation, parity, and mean monthly temperature. Of the 522 896 eligible singleton deliveries, 8689 (1.66%) mothers developed preeclampsia. Total antenatal UV-B exposure ranged from 43.18 to 101.11 kJ/m2 and was associated with reduced risk of preeclampsia with evidence of a dose-response relationship (highest quintile of exposure: adjusted odds ratio, 0.57; 95% CI, 0.44-0.72; P<0.001). Associations were demonstrated for UV-B exposure in all 3 trimesters. Conclusions The seasonal patterning of preeclampsia may be mediated through low maternal vitamin D concentration in winter resulting from low UV-B radiation. Interventional studies are required to determine whether vitamin D supplements or UV-B-emitting light boxes can reduce the seasonal patterning of preeclampsia.

Air Pollution, housing and respirfatory tract Infections in Children: NatIonal birth Cohort study (PICNIC): study protocol.

INTRODUCTION: Respiratory tract infections (RTIs) are the most common reason for hospital admission among children <5 years in the UK. The relative contribution of ambient air pollution exposure and adverse housing conditions to RTI admissions in young children is unclear and has not been assessed in a UK context. METHODS AND ANALYSIS: The aim of the PICNIC study (Air Pollution, housing and respiratory tract Infections in Children: NatIonal birth Cohort Study) is to quantify the extent to which in-utero, infant and childhood exposures to ambient air pollution and adverse housing conditions are associated with risk of RTI admissions in children <5 years old. We will use national administrative data birth cohorts, including data from all children born in England in 2005-2014 and in Scotland in 1997-2020, created via linkage between civil registration, maternity and hospital admission data sets. We will further enhance these cohorts via linkage to census data on housing conditions and socioeconomic position and small area-level data on ambient air pollution and building characteristics. We will use time-to-event analyses to examine the association between air pollution, housing characteristics and the risk of RTI admissions in children, calculate population attributable fractions for ambient air pollution and housing characteristics, and use causal mediation analyses to explore the mechanisms through which housing and air pollution influence the risk of infant RTI admission. ETHICS, EXPECTED IMPACT AND DISSEMINATION: To date, we have obtained approval from six ethics and information governance committees in England and two in Scotland. Our results will inform parents, national and local governments, the National Health Service and voluntary sector organisations of the relative contribution of adverse housing conditions and air pollution to RTI admissions in young children. We will publish our results in open-access journals and present our results to the public via parent groups and social media and on the PICNIC website. Code and metadata will be published on GitHub.

Life Course Air Pollution Exposure and Cognitive Decline: Modelled Historical Air Pollution Data and the Lothian Birth Cohort 1936.

BACKGROUND: Air pollution has been consistently linked with dementia and cognitive decline. However, it is unclear whether risk is accumulated through long-term exposure or whether there are sensitive/critical periods. A key barrier to clarifying this relationship is the dearth of historical air pollution data. OBJECTIVE: To demonstrate the feasibility of modelling historical air pollution data and using them in epidemiologicalmodels. METHODS: Using the EMEP4UK atmospheric chemistry transport model, we modelled historical fine particulate matter (PM2.5) concentrations for the years 1935, 1950, 1970, 1980, and 1990 and combined these with contemporary modelled data from 2001 to estimate life course exposure in 572 participants in the Lothian Birth Cohort 1936 with lifetime residential history recorded. Linear regression and latent growth models were constructed using cognitive ability (IQ) measured by the Moray House Test at the ages of 11, 70, 76, and 79 years to explore the effects of historical air pollution exposure. Covariates included sex, IQ at age 11 years, social class, and smoking. RESULTS: Higher air pollution modelled for 1935 (when participants would have been in utero) was associated with worse change in IQ from age 11-70 years (ß = -0.006, SE = 0.002, p = 0.03) but not cognitive trajectories from age 70-79 years (p > 0.05). There was no support for other critical/sensitive periods of exposure or an accumulation of risk (all p > 0.05). CONCLUSION: The life course paradigm is essential in understanding cognitive decline and this is the first study to examine life course air pollution exposure in relation to cognitive health.

Unemployment, mortality and the problem of health-related selection: evidence from the Scottish and England & Wales (ONS) longitudinal studies.

Testing whether unemployment causes health deterioration is complicated because failing health may increase the probability of unemployment. In some previous studies of unemployment and mortality a 'wear-off' period is used to exclude any deaths occurring in the first few years after employment status was observed. It is assumed that selection effects will wear-off during this period. In this article the effectiveness of using wear-off periods is tested. Using data from the Scottish Longitudinal Study and the England and Wales Longitudinal Study, logistic regression models were used for estimating the odds of death in a given time period after the 1991 Census for those aged 35-64 in 1991. The odds ratios for the different economic positions (in work, unemployed, retired, permanently sick and other inactive) were compared, as well as the changes in risk associated with cumulatively increasing the length of wear-off prior to follow-up. No evidence was found of health-related selection for the unemployed in 1991. This observation was consistent across both studies. This suggests that the use of the five year wear-off period in many studies of mortality and unemployment may be an ineffective and unnecessary technique for mitigating the effects of health-related selection.

UVA and Seasonal Patterning of 56 370 Myocardial Infarctions Across Scotland, 2000-2011.

Background Myocardial infarction exhibits seasonal patterning, with higher amplitude at increased latitude. Epidemiological evidence suggests that sunlight is protective against cardiovascular disease, independent of ambient temperature, but ultraviolet B-mediated vitamin D production has been discounted as causal. We aimed to determine whether ultraviolet A is associated with the seasonal patterning of myocardial infarction. Methods and Results Routine hospitalization data were used to determine monthly incidence of myocardial infarction in Scotland between 2000 and 2011. Small-area-level aggregated data were obtained on ambient temperature from the Meteorological Office and ultraviolet A and ultraviolet B irradiance from NASA satellites. Autoregressive distributed lag models were run for ultraviolet A and myocardial infarction, including adjustment for ambient temperature and ultraviolet B. Monthly incidence of myocardial infarction displayed winter peaks and summer troughs superimposed on the underlying trend, with a mean amplitude of 0.31 (95% CI: 0.21, 0.41) myocardial infarctions per 100 000 population per month. Ultraviolet A exposure was inversely associated with myocardial infarction independent of ambient temperature (coefficient, -0.05; 95% CI, -0.09, -0.01; P=0.015) and ultraviolet B UVB (coefficient, -0.05; 95% CI, -0.09, -0.02; P=0.004). Conclusions Further research is required to explore whether an ultraviolet-mediated mechanism different to vitamin D, such as nitric oxide-mediated vasodilatation, may play a causal role in the seasonal and geographical patterning of myocardial infarction.