Development of the Impacts of Cycling Tool (ICT): A modelling study and web tool for evaluating health and environmental impacts of cycling uptake.

BACKGROUND: A modal shift to cycling has the potential to reduce greenhouse gas emissions and provide health co-benefits. Methods, models, and tools are needed to estimate the potential for cycling uptake and communicate to policy makers the range of impacts this would have. METHODS AND FINDINGS: The Impacts of Cycling Tool (ICT) is an open source model with a web interface for visualising travel patterns and comparing the impacts of different scenarios of cycling uptake. It is currently applied to England. The ICT allows users to visualise individual and trip-level data from the English National Travel Survey (NTS), 2004-2014 sample, 132,000 adults. It models scenarios in which there is an increase in the proportion of the population who cycle regularly, using a distance-based propensity approach to model which trips would be cycled. From this, the model estimates likely impact on travel patterns, health, and greenhouse gas emissions. Estimates of nonoccupational physical activity are generated by fusing the NTS with the English Active People Survey (APS, 2013-2014, 559,515 adults) to create a synthetic population. Under 'equity' scenarios, we investigate what would happen if cycling levels increased equally among all age and gender categories, as opposed to in proportion to the profile of current cyclists. Under electric assist bike (pedelecs or 'e-bike') scenarios, the probability of cycling longer trips increases, based on the e-bike data from the Netherlands, 2013-2014 Dutch Travel Survey (50,868 adults).Outcomes are presented across domains including transport (trip duration and trips by mode), health (physical activity levels, years of life lost), and car transport-related CO2 emissions. Results can be visualised for the whole population and various subpopulations (region, age, gender, and ethnicity). The tool is available at www.pct.bike/ict. If the proportion of the English population who cycle regularly increased from 4.8% to 25%, then there would be notable reductions in car miles and passenger related CO2 emissions (2.2%) and health benefits (2.1% reduction in years of life lost due to premature mortality). If the new cyclists had access to e-bikes, then mortality reductions would be similar, while the reduction in car miles and CO2 emissions would be larger (2.7%). If take-up of cycling occurred equally by gender and age (under 80 years), then health benefits would be marginally greater (2.2%) but reduction in CO2 slightly smaller (1.8%). The study is limited by the quality and comparability of the input data (including reliance on self-report behaviours). As with all modelling studies, many assumptions are required and potentially important pathways excluded (e.g. injury, air pollution, and noise pollution). CONCLUSION: This study demonstrates a generalisable approach for using travel survey data to model scenarios of cycling uptake that can be applied to a wide range of settings. The use of individual-level data allows investigation of a wide range of outcomes, and variation across subgroups. Future work should investigate the sensitivity of results to assumptions and omissions, and if this varies across setting.

The current and potential health benefits of the National Health Service Health Check cardiovascular disease prevention programme in England: A microsimulation study.

BACKGROUND: The National Health Service (NHS) Health Check programme was introduced in 2009 in England to systematically assess all adults in midlife for cardiovascular disease risk factors. However, its current benefit and impact on health inequalities are unknown. It is also unclear whether feasible changes in how it is delivered could result in increased benefits. It is one of the first such programmes in the world. We sought to estimate the health benefits and effect on inequalities of the current NHS Health Check programme and the impact of making feasible changes to its implementation. METHODS AND FINDINGS: We developed a microsimulation model to estimate the health benefits (incident ischaemic heart disease, stroke, dementia, and lung cancer) of the NHS Health Check programme in England. We simulated a population of adults in England aged 40-45 years and followed until age 100 years, using data from the Health Survey of England (2009-2012) and the English Longitudinal Study of Aging (1998-2012), to simulate changes in risk factors for simulated individuals over time. We used recent programme data to describe uptake of NHS Health Checks and of 4 associated interventions (statin medication, antihypertensive medication, smoking cessation, and weight management). Estimates of treatment efficacy and adherence were based on trial data. We estimated the benefits of the current NHS Health Check programme compared to a healthcare system without systematic health checks. This counterfactual scenario models the detection and treatment of risk factors that occur within 'routine' primary care. We also explored the impact of making feasible changes to implementation of the programme concerning eligibility, uptake of NHS Health Checks, and uptake of treatments offered through the programme. We estimate that the NHS Health Check programme prevents 390 (95% credible interval 290 to 500) premature deaths before 80 years of age and results in an additional 1,370 (95% credible interval 1,100 to 1,690) people being free of disease (ischaemic heart disease, stroke, dementia, and lung cancer) at age 80 years per million people aged 40-45 years at baseline. Over the life of the cohort (i.e., followed from 40-45 years to 100 years), the changes result in an additional 10,000 (95% credible interval 8,200 to 13,000) quality-adjusted life years (QALYs) and an additional 9,000 (6,900 to 11,300) years of life. This equates to approximately 300 fewer premature deaths and 1,000 more people living free of these diseases each year in England. We estimate that the current programme is increasing QALYs by 3.8 days (95% credible interval 3.0-4.7) per head of population and increasing survival by 3.3 days (2.5-4.1) per head of population over the 60 years of follow-up. The current programme has a greater absolute impact on health for those living in the most deprived areas compared to those living in the least deprived areas (4.4 [2.7-6.5] days of additional quality-adjusted life per head of population versus 2.8 [1.7-4.0] days; 5.1 [3.4-7.1] additional days lived per head of population versus 3.3 [2.1-4.5] days). Making feasible changes to the delivery of the existing programme could result in a sizable increase in the benefit. For example, a strategy that combines extending eligibility to those with preexisting hypertension, extending the upper age of eligibility to 79 years, increasing uptake of health checks by 30%, and increasing treatment rates 2.5-fold amongst eligible patients (i.e., 'maximum potential' scenario) results in at least a 3-fold increase in benefits compared to the current programme (1,360 premature deaths versus 390; 5,100 people free of 1 of the 4 diseases versus 1,370; 37,000 additional QALYs versus 10,000; 33,000 additional years of life versus 9,000). Ensuring those who are assessed and eligible for statins receive statins is a particularly important strategy to increase benefits. Estimates of overall benefit are based on current incidence and management, and future declines in disease incidence or improvements in treatment could alter the actual benefits observed in the long run. We have focused on the cardiovascular element of the NHS Health Check programme. Some important noncardiovascular health outcomes (e.g., chronic obstructive pulmonary disease [COPD] prevention from smoking cessation and cancer prevention from weight loss) and other parts of the programme (e.g., brief interventions to reduce harmful alcohol consumption) have not been modelled. CONCLUSIONS: Our model indicates that the current NHS Health Check programme is contributing to improvements in health and reducing health inequalities. Feasible changes in the organisation of the programme could result in more than a 3-fold increase in health benefits.

Social class, social mobility and alcohol-related disorders in Swedish men and women: A study of four generations.

OBJECTIVES: To investigate whether and how social class and social mobility in grandparents and parents predict alcohol-related disorders (ARDs) in males and females aged 12+ years, and whether intergenerational social prediction of ARDs varies across time periods. METHODS: The study sample included four successive generations (G) of Swedish families from the Uppsala Birth Cohort Multigenerational Study: G0 born 1851-1912; G1 born 1915-1929; G2 born 1940-1964 and G3 born 1965-1989. Two study populations were created, each consisting of grandparents, parents and offspring: population I 'G0-G1-G2' (offspring n = 18 430) and population II 'G1-G2-G3' (offspring n = 26 469). Registers and archives provided data on ancestors' socio-demographic factors and ARD history, together with offspring ARD development between 1964-2008. Cox regression models examined the hazard of offspring ARD development according to grandparental social class and grandparental-to-parental social trajectories, controlling for offspring birth year, grandmother's and mother's marital status and parental ARDs. RESULTS: Disadvantaged grandparental social class predicted increased ARD risk in offspring in population I, although the effect attenuated and became non-significant in males after adjusting for parental characteristics (adjusted hazard ratio (HR) = 1.80 (95%CI; 1.07, 3.03) in females, HR = 1.32 (95%CI; 0.93, 1.89) in males). In population II, no increase in ARD risk by grandparental social was evident. In both populations, males were at the highest ARD risk if both parents and grandparents belonged to disadvantaged social class (population I: HR = 1.82 (95%CI; 1.22-2.72); population II: HR = 1.68 (95%CI; 1.02-2.76)). CONCLUSIONS: Intergenerational social patterning of ARDs appears to be time-contextual and gender-specific. The role of grandparental social class in developing ARDs in grandchildren seems to decline over time, while persistent grandparental-to-parental social disadvantage remains associated with higher ARD risk in males. When targeting higher risk groups, continuity of familial social disadvantage, particularly among males, should be considered.

Predictors of the frequency and subjective experience of cycling near misses: Findings from the first two years of the UK Near Miss Project.

Using 2014 and 2015 data from the UK Near Miss Project, this paper examines the stability of self-report incident rates for cycling near misses across these two years. It further examines the stability of the individual-level predictors of experiencing a near miss, including what influences the scariness of an incident. The paper uses three questions asked for only in 2015, which allow further exploration of factors shaping near miss rates and impacts of incidents. Firstly, a respondent's level of cycling experience; secondly, whether an incident was perceived as deliberate; and finally, whether the respondent themselves described the incident as a 'near miss' (as opposed to only a frightening and/or annoying non-injury incident). Using this data, we find a decline of almost a third in incident rates in 2015 compared to 2014, which we believe is likely to be largely an artefact due to differences in reporting rates. This suggests caution about interpreting small fluctuations in subjectively reported near miss rates. However, in both years near miss rates are many times more frequent than injury collisions. In both years of data collection our findings are very similar in terms of the patterning of incident types, and how frightening different incident categories are, which increases confidence in these findings. We find that new cyclists experience very high incident rates compared to other cyclists, and test a conceptual model explaining how perceived deliberateness, near-miss status, and scariness are connected. For example, incidents that are perceived to be deliberate are more likely to be experienced as very frightening, independent of their 'near miss' status.

From cradle to grave: tracking socioeconomic inequalities in mortality in a cohort of 11†868 men and women born in Uppsala, Sweden, 1915-1929.

BACKGROUND: Ample evidence has shown that early-life social conditions are associated with mortality later in life. However, little attention has been given to the strength of these effects across specific age intervals from birth to old age. In this paper, we study the effect of the family's socioeconomic position and mother's marital status at birth on all-cause mortality at different age intervals in a Swedish cohort of 11 868 individuals followed across their lifespan. METHODS: Using the Uppsala Birth Cohort Multigenerational Study, we fitted Cox regression models to estimate age-varying HRs of all-cause mortality according to mother's marital status and family's socioeconomic position. RESULTS: Mother's marital status and family's socioeconomic position at birth were associated with higher mortality rates throughout life (HR 1.18 (95% CI 1.12 to 1.26) for unmarried mothers; 1.19 (95% CI 1.12 to 1.25) for low socioeconomic position). While the effect of family's socioeconomic position showed little variation across different age groups, the effect of marital status was stronger for infant mortality (HR 1.47 (95% CI 1.23 to 1.76); p=0.04 for heterogeneity). The results remained robust when early life and adult mediator variables were included. CONCLUSIONS: Family's socioeconomic position and mother's marital status involve different dimensions of social stratification with independent effects on mortality throughout life. Our findings support the importance of improving early-life conditions in order to enhance healthy ageing.

Preclinical Assessment of Viral Vectored and Protein Vaccines Targeting the Duffy-Binding Protein Region II of Plasmodium Vivax.

Malaria vaccine development has largely focused on Plasmodium falciparum; however, a reawakening to the importance of Plasmodium vivax has spurred efforts to develop vaccines against this difficult to treat and at times severe form of relapsing malaria, which constitutes a significant proportion of human malaria cases worldwide. The almost complete dependence of P. vivax red blood cell invasion on the interaction of the P. vivax Duffy-binding protein region II (PvDBP_RII) with the human Duffy antigen receptor for chemokines (DARC) makes this antigen an attractive vaccine candidate against blood-stage P. vivax. Here, we generated both preclinical and clinically compatible adenoviral and poxviral vectored vaccine candidates expressing the Salvador I allele of PvDBP_RII - including human adenovirus serotype 5 (HAdV5), chimpanzee adenovirus serotype 63 (ChAd63), and modified vaccinia virus Ankara (MVA) vectors. We report on the antibody and T cell immunogenicity of these vaccines in mice or rabbits, either used alone in a viral vectored prime-boost regime or in "mixed-modality" adenovirus prime - protein-in--adjuvant boost regimes (using a recombinant PvDBP_RII protein antigen formulated in Montanide(®)ISA720 or Abisco(®)100 adjuvants). Antibodies induced by these regimes were found to bind to native parasite antigen from P. vivax infected Thai patients and were capable of inhibiting the binding of PvDBP_RII to its receptor DARC using an in vitro binding inhibition assay. In recent years, recombinant ChAd63 and MVA vectors have been quickly translated into human clinical trials for numerous antigens from P. falciparum as well as a growing number of other pathogens. The vectors reported here are immunogenic in small animals, elicit antibodies against PvDBP_RII, and have recently entered clinical trials, which will provide the first assessment of the safety and immunogenicity of the PvDBP_RII antigen in humans.

Social inequality in pre-pregnancy BMI and gestational weight gain in the first and second pregnancy among women in Sweden.

BACKGROUND: High pre-pregnancy body mass index (BMI) and inappropriate gestational weight gain (GWG) are associated with adverse short and long-term maternal and neonatal outcomes and may act as modifiable risk factors on the path to overweight/obesity, but their social patterning is not well established. This study investigates the association of education with BMI and GWG across two consecutive pregnancies. METHODS: The study includes 163,352 Swedish women, having their first and second singleton birth in 1982-2010. In both pregnancies, we investigated the association of women's education with (1) pre-pregnancy weight status and (2) adequacy of GWG. We used multinomial logistic regression, adjusting for child's birth year, mother's age and smoking status. RESULTS: Overall, the odds of starting either pregnancy at an unhealthy BMI were higher among women with a low education compared to more highly-educated women. Lower education also predicted a greater increase in BMI between pregnancies, with this effect greatest among women with excessive GWG in the first pregnancy (p<0.0001 for interaction). Education was also inversely associated with odds of excessive GWG in both pregnancies among healthy weight status women, but this association was absent or even weakly reversed among overweight and obese women. CONCLUSIONS: Lower educated women had the largest BMI increase between pregnancies, and these inequalities were greatest among women with excessive GWG in the first pregnancy. The importance of a healthy pre-pregnancy BMI, appropriate GWG and a healthy postpartum weight should be communicated to all women, which may assist in reducing existing social inequalities in body weight.

Daylight saving time as a potential public health intervention: an observational study of evening daylight and objectively-measured physical activity among 23,000 children from 9 countries.

BACKGROUND: It has been proposed that introducing daylight saving measures could increase children's physical activity, but there exists little research on this issue. This study therefore examined associations between time of sunset and activity levels, including using the bi-annual 'changing of the clocks' as a natural experiment. METHODS: 23,188 children aged 5-16 years from 15 studies in nine countries were brought together in the International Children's Accelerometry Database. 439 of these children were of particular interest for our analyses as they contributed data both immediately before and after the clocks changed. All children provided objectively-measured physical activity data from Actigraph accelerometers, and we used their average physical activity level (accelerometer counts per minute) as our primary outcome. Date of accelerometer data collection was matched to time of sunset, and to weather characteristics including daily precipitation, humidity, wind speed and temperature. RESULTS: Adjusting for child and weather covariates, we found that longer evening daylight was independently associated with a small increase in daily physical activity. Consistent with a causal interpretation, the magnitude of these associations was largest in the late afternoon and early evening and these associations were also evident when comparing the same child just before and just after the clocks changed. These associations were, however, only consistently observed in the five mainland European, four English and two Australian samples (adjusted, pooled effect sizes 0.03-0.07 standard deviations per hour of additional evening daylight). In some settings there was some evidence of larger associations between daylength and physical activity in boys. There was no evidence of interactions with weight status or maternal education, and inconsistent findings for interactions with age. CONCLUSIONS: In Europe and Australia, evening daylight seems to play a causal role in increasing children's activity in a relatively equitable manner. Although the average increase in activity is small in absolute terms, these increases apply across all children in a population. Moreover, these small effect sizes actually compare relatively favourably with the typical effect of intensive, individual-level interventions. We therefore conclude that, by shifting the physical activity mean of the entire population, the introduction of additional daylight saving measures could yield worthwhile public health benefits.

Family history of education predicts eating disorders across multiple generations among 2 million Swedish males and females.

PURPOSE: To investigate which facets of parent and grandparent socio-economic position (SEP) are associated with eating disorders (ED), and how this varies by ED subtype and over time. METHODS: Total-population cohort study of 1,040,165 females and 1,098,188 males born 1973-1998 in Sweden, and followed for inpatient or outpatient ED diagnoses until 2010. Proportional hazards models estimated associations with parental education, income and social class, and with grandparental education and income. RESULTS: 15,747 females and 1051 males in our sample received an ED diagnosis, with rates increasing in both sexes over time. ED incidence in females was independently predicted by greater educational level among the father, mother and maternal grandparents, but parent social class and parental income showed little or no independent effect. The associations with education were equally strong for anorexia nervosa, bulimia nervosa and ED not-otherwise-specified, and had increased over time. Among males, an apparently similar pattern was seen with respect to anorexia nervosa, but non-anorexia ED showed no association with parental education and an inverse association with parental income. CONCLUSIONS: Family history of education predicts ED in gender- and disorder-specific ways, and in females the effect is observed across multiple generations. Particularly given that these effects may have grown stronger in more recent cohorts, these findings highlight the need for further research to clarify the underlying mechanisms and identify promising targets for prevention. Speculatively, one such mechanism may involve greater internal and external demands for academic success in highly educated families.

New walking and cycling routes and increased physical activity: one- and 2-year findings from the UK iConnect Study.

OBJECTIVES: We evaluated the effects of providing new high-quality, traffic-free routes for walking and cycling on overall levels of walking, cycling, and physical activity. METHODS: 1796 adult residents in 3 UK municipalities completed postal questionnaires at baseline (2010) and 1-year follow-up (2011), after the construction of the new infrastructure. 1465 adults completed questionnaires at baseline and 2-year follow-up (2012). Transport network distance from home to infrastructure defined intervention exposure and provided a basis for controlled comparisons. RESULTS: Living nearer the infrastructure did not predict changes in activity levels at 1-year follow-up but did predict increases in activity at 2 years relative to those living farther away (15.3 additional minutes/week walking and cycling per km nearer; 12.5 additional minutes/week of total physical activity). The effects were larger among participants with no car. CONCLUSIONS: These new local routes may mainly have displaced walking or cycling trips in the short term but generated new trips in the longer term, particularly among those unable to access more distant destinations by car. These findings support the potential for walking and cycling infrastructure to promote physical activity.

Effectiveness and equity impacts of town-wide cycling initiatives in England: a longitudinal, controlled natural experimental study.

Cycling confers health and environmental benefits, but few robust studies have evaluated large-scale programmes to promote cycling. In England, recent years have seen substantial, town-wide cycling initiatives in six Cycling Demonstration Towns (funded 2005-2011) and 12 Cycling Cities and Towns (funded 2008-2011). The initiatives involved mixtures of capital investment (e.g. cycle lanes) and revenue investment (e.g. cycle training), tailored to each town. This controlled before-after natural experimental study used English census data to examine impacts on the prevalence of travelling to work by bicycle and other modes, comparing changes in the intervention towns with changes in three comparison groups (matched towns, unfunded towns and a national comparison group). We also compared effects between more and less deprived areas, and used random-effects meta-analysis to compare intervention effects between towns. Among 1.3 million commuters in 18 intervention towns, we found that the prevalence of cycling to work rose from 5.8% in 2001 to 6.8% in 2011. This represented a significant increase relative to all three comparison groups (e.g. +0.69 (95% CI 0.60,0.77) percentage points for intervention vs. matched towns). Walking to work also increased significantly compared with comparison towns, while driving to work decreased and public transport use was unchanged. These effects were observed across all fifths of area deprivation, with larger relative changes in deprived areas. There was substantial variation in effect sizes between towns, however, and the average town-level effect on cycling was non-significant (+0.29 (-0.26,0.84) percentage points for intervention vs. matched towns). We conclude that to date, cycling to work has increased (and driving to work decreased) in the intervention towns, in a relatively equitable manner. The variation in effects between towns indicates uncertainty regarding the likely impact of comparable investment in future towns. Nevertheless these results support the case for implementing and evaluating further town-wide cycling initiatives.

Sibling configuration predicts individual and descendant socioeconomic success in a modern post-industrial society.

Growing up with many siblings, at least in the context of modern post-industrial low fertility, low mortality societies, is predictive of relatively poor performance on school tests in childhood, lower levels of educational attainment, and lower income throughout adulthood. Recent studies further indicate these relationships hold across generations, so that the descendants of those who grow up with many siblings are also at an apparent socioeconomic disadvantage. In this paper we add to this literature by considering whether such relationships interact with the sex and relative age of siblings. To do this we utilise a unique Swedish multigenerational birth cohort study that provides sibling configuration data on over 10,000 individuals born in 1915-1929, plus all their direct genetic descendants to the present day. Adjusting for parental and birth characteristics, we find that the 'socioeconomic cost' of growing up in a large family is independent of both the sex of siblings and the sex of the individual. However, growing up with several older as opposed to several younger siblings is predictive of relatively poor performance on school tests and a lower likelihood of progression to tertiary education. This later-born disadvantage also holds across generations, with the children of those with many older siblings achieving lower levels of educational attainment. Despite these differences, we find that while individual and descendant income is negatively related to the number of siblings, it is not influenced by the relative age of siblings. Thus, our findings imply that the educational disadvantage of later-born children, demonstrated here and in numerous other studies, does not necessarily translate into reduced earnings in adulthood. We discuss potential explanations for this pattern of results, and consider some important directions for future research into sibling configuration and wellbeing in modern societies.

Walking, cycling and driving to work in the English and Welsh 2011 census: trends, socio-economic patterning and relevance to travel behaviour in general.

OBJECTIVES: Increasing walking and cycling, and reducing motorised transport, are health and environmental priorities. This paper examines levels and trends in the use of different commute modes in England and Wales, both overall and with respect to small-area deprivation. It also investigates whether commute modal share can serve as a proxy for travel behaviour more generally. METHODS: 23.7 million adult commuters reported their usual main mode of travelling to work in the 2011 census in England and Wales; similar data were available for 1971-2001. Indices of Multiple Deprivation were used to characterise socio-economic patterning. The National Travel Survey (2002-2010) was used to examine correlations between commute modal share and modal share of total travel time. These correlations were calculated across 150 non-overlapping populations defined by region, year band and income. RESULTS: Among commuters in 2011, 67.1% used private motorised transport as their usual main commute mode (-1.8 percentage-point change since 2001); 17.8% used public transport (+1.8% change); 10.9% walked (-0.1% change); and 3.1% cycled (+0.1% change). Walking and, to a marginal extent, cycling were more common among those from deprived areas, but these gradients had flattened over the previous decade to the point of having essentially disappeared for cycling. In the National Travel Survey, commute modal share and total modal share were reasonably highly correlated for private motorised transport (r = 0.94), public transport (r = 0.96), walking (r = 0.88 excluding London) and cycling (r = 0.77). CONCLUSIONS: England and Wales remain car-dependent, but the trends are slightly more encouraging. Unlike many health behaviours, it is more common for socio-economically disadvantaged groups to commute using physically active modes. This association is, however, weakening and may soon reverse for cycling. At a population level, commute modal share provides a reasonable proxy for broader travel patterns, enhancing the value of the census in characterising background trends and evaluating interventions.

Who uses new walking and cycling infrastructure and how? Longitudinal results from the UK iConnect study.

OBJECTIVE: To examine how adults use new local walking and cycling routes, and what characteristics predict use. METHODS: 1849 adults completed questionnaires in 2010 and 2011, before and after the construction of walking and cycling infrastructure in three UK municipalities. 1510 adults completed questionnaires in 2010 and 2012. The 2010 questionnaire measured baseline characteristics; the follow-up questionnaires captured infrastructure use. RESULTS: 32% of participants reported using the new infrastructure in 2011, and 38% in 2012. Walking for recreation was by far the most common use. In both follow-up waves, use was independently predicted by higher baseline walking and cycling (e.g. 2012 adjusted rate ratio 2.09 (95% CI 1.55, 2.81) for >450 min/week vs. none). Moreover, there was strong specificity by mode and purpose, e.g. baseline walking for recreation specifically predicted walking for recreation on the infrastructure. Other independent predictors included living near the infrastructure, better general health and higher education or income. CONCLUSIONS: The new infrastructure was well-used by local adults, and this was sustained over two years. Thus far, however, the infrastructure may primarily have attracted existing walkers and cyclists, and may have catered more to the socio-economically advantaged. This may limit its impacts on population health and health equity.

Associations between active commuting and physical and mental wellbeing.

OBJECTIVE: To examine whether a relationship exists between active commuting and physical and mental wellbeing. METHOD: In 2009, cross-sectional postal questionnaire data were collected from a sample of working adults (aged 16 and over) in the Commuting and Health in Cambridge study. Travel behaviour and physical activity were ascertained using the Recent Physical Activity Questionnaire (RPAQ) and a seven-day travel-to-work recall instrument from which weekly time spent in active commuting (walking and cycling) was derived. Physical and mental wellbeing were assessed using the Medical Outcomes Study Short Form survey (SF-8). Associations were tested using multivariable linear regression. RESULTS: An association was observed between physical wellbeing (PCS-8) score and time spent in active commuting after adjustment for other physical activity (adjusted regression coefficients 0.48, 0.79 and 1.21 for 30-149 min/week, 150-224 min/week and ≥ 225 min/week respectively versus < 30 min/week, p=0.01 for trend; n=989). No such relationship was found for mental wellbeing (MCS-8) (p=0.52). CONCLUSION: Greater time spent actively commuting is associated with higher levels of physical wellbeing. Longitudinal studies should examine the contribution of changing levels of active commuting and other forms of physical activity to overall health and wellbeing.

The utility of Plasmodium berghei as a rodent model for anti-merozoite malaria vaccine assessment.

Rodent malaria species Plasmodium yoelii and P. chabaudi have been widely used to validate vaccine approaches targeting blood-stage merozoite antigens. However, increasing data suggest the P. berghei rodent malaria may be able to circumvent vaccine-induced anti-merozoite responses. Here we confirm a failure to protect against P. berghei, despite successful antibody induction against leading merozoite antigens using protein-in-adjuvant or viral vectored vaccine delivery. No subunit vaccine approach showed efficacy in mice following immunization and challenge with the wild-type P. berghei strains ANKA or NK65, or against a chimeric parasite line encoding a merozoite antigen from P. falciparum. Protection was not improved in knockout mice lacking the inhibitory Fc receptor CD32b, nor against a Δsmac P. berghei parasite line with a non-sequestering phenotype. An improved understanding of the mechanisms responsible for protection, or failure of protection, against P. berghei merozoites could guide the development of an efficacious vaccine against P. falciparum.

Socio-economic position over the life course and all-cause, and circulatory diseases mortality at age 50-87 years: results from a Swedish birth cohort.

Both child and adult socio-economic position (SEP) predict adult mortality, but little is known about the variation in the impact of SEP across the life course. The Uppsala Birth Cohort Study is a representative birth cohort born 1915-1929 in Uppsala, Sweden. For the 5,138 males and 5,069 females alive in 1980, SEP was available at birth; in adulthood (age 31-45); and in later life (age 51-65). Follow-up for mortality (all-cause, and circulatory disease) was from 1980 to 2002. To test which life course model best described the association between SEP and mortality, we compared the fit of a series of nested Cox proportional hazards regression models (representing either the critical, accumulation or sensitive period models) with a fully saturated model. For all-cause mortality in both genders, the sensitive period model best described the influence of SEP across the life course with a heightened effect in later adult life (males: Hazard Ratio (95 % CI) for advantaged SEP: 0.89 (0.81-0.97) at birth, 0.90 (0.81-0.98) in adulthood, 0.74 (0.67-0.82) in later life; females: 0.87 (0.78-0.98), 0.95 (0.86-1.06), 0.73 (0.64-0.83)). The effect of SEP on circulatory diseases mortality in males was cumulative (HR: 0.84 (0.80-0.87) per unit time in advantaged SEP). For circulatory disease mortality among females, a sensitive period model was selected due to SEP in later adult life (HR: 0.64 (0.52-0.80)). These findings suggest that reducing inequality throughout the life course might reduce all-cause and circulatory disease mortality.

Low fertility increases descendant socioeconomic position but reduces long-term fitness in a modern post-industrial society.

Adaptive accounts of modern low human fertility argue that small family size maximizes the inheritance of socioeconomic resources across generations and may consequently increase long-term fitness. This study explores the long-term impacts of fertility and socioeconomic position (SEP) on multiple dimensions of descendant success in a unique Swedish cohort of 14 000 individuals born during 1915-1929. We show that low fertility and high SEP predict increased descendant socioeconomic success across four generations. Furthermore, these effects are multiplicative, with the greatest benefits of low fertility observed when SEP is high. Low fertility and high SEP do not, however, predict increased descendant reproductive success. Our results are therefore consistent with the idea that modern fertility limitation represents a strategic response to the local costs of rearing socioeconomically competitive offspring, but contradict adaptive models suggesting that it maximizes long-term fitness. This indicates a conflict in modern societies between behaviours promoting socioeconomic versus biological success. This study also makes a methodological contribution, demonstrating that the number of offspring strongly predicts long-term fitness and thereby validating use of fertility data to estimate current selective pressures in modern populations. Finally, our findings highlight that differences in fertility and SEP can have important long-term effects on the persistence of social inequalities across generations.

Healthy travel and the socio-economic structure of car commuting in Cambridge, UK: a mixed-methods analysis.

Car use is associated with substantial health and environmental costs but research in deprived populations indicates that car access may also promote psychosocial well-being within car-oriented environments. This mixed-method (quantitative and qualitative) study examined this issue in a more affluent setting, investigating the socio-economic structure of car commuting in Cambridge, UK. Our analyses involved integrating self-reported questionnaire data from 1142 participants in the Commuting and Health in Cambridge study (collected in 2009) and in-depth interviews with 50 participants (collected 2009-2010). Even in Britain's leading 'cycling city', cars were a key resource in bridging the gap between individuals' desires and their circumstances. This applied both to long-term life goals such as home ownership and to shorter-term challenges such as illness. Yet car commuting was also subject to constraints, with rush hour traffic pushing drivers to start work earlier and with restrictions on, or charges for, workplace parking pushing drivers towards multimodal journeys (e.g. driving to a 'park-and-ride' site then walking). These patterns of car commuting were socio-economically structured in several ways. First, the gradient of housing costs made living near Cambridge more expensive, affecting who could 'afford' to cycle and perhaps making cycling the more salient local marker of Bourdieu's class distinction. Nevertheless, cars were generally affordable in this relatively affluent, highly-educated population, reducing the barrier which distance posed to labour-force participation. Finally, having the option of starting work early required flexible hours, a form of job control which in Britain is more common among higher occupational classes. Following a social model of disability, we conclude that socio-economic advantage can make car-oriented environments less disabling via both greater affluence and greater job control, and in ways manifested across the full socio-economic range. This suggests the importance of combining individual-level 'healthy travel' interventions with measures aimed at creating travel environments in which all social groups can pursue healthy and satisfying lives.