[Show abstract][Hide abstract] ABSTRACT: Background
Existing reviews identify numerous studies of the relationship between urban built environment characteristics and obesity. These reviews do not generally distinguish between cross-sectional observational studies using single equation analytical techniques and other studies that may support more robust causal inferences. More advanced analytical techniques, including the use of instrumental variables and regression discontinuity designs, can help mitigate biases that arise from differences in observable and unobservable characteristics between intervention and control groups, and may represent a realistic alternative to scarcely-used randomised experiments. This review sought first to identify, and second to compare the results of analyses from, studies using more advanced analytical techniques or study designs.Methods
In March 2013, studies of the relationship between urban built environment characteristics and obesity were identified that incorporated (i) more advanced analytical techniques specified in recent UK Medical Research Council guidance on evaluating natural experiments, or (ii) other relevant methodological approaches including randomised experiments, structural equation modelling or fixed effects panel data analysis.ResultsTwo randomised experimental studies and twelve observational studies were identified. Within-study comparisons of results, where authors had undertaken at least two analyses using different techniques, indicated that effect sizes were often critically affected by the method employed, and did not support the commonly held view that cross-sectional, single equation analyses systematically overestimate the strength of association.Conclusions
Overall, the use of more advanced methods of analysis does not appear necessarily to undermine the observed strength of association between urban built environment characteristics and obesity when compared to more commonly-used cross-sectional, single equation analyses. Given observed differences in the results of studies using different techniques, further consideration should be given to how evidence gathered from studies using different analytical approaches is appraised, compared and aggregated in evidence synthesis.
International Journal of Behavioral Nutrition and Physical Activity 11/2014; 11(1):142. · 3.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 276 GPS-tracked commute trips from a free-living sample of adults were analysed.•GPS routes were compared with GIS-modelled shortest routes.•GIS may be acceptable for distance estimation for active commuting.•GPS should be used to obtain accurate estimates of environmental contexts.•Method chosen will likely influence conclusions on health implications of commuting.
[Show abstract][Hide abstract] ABSTRACT: Objective
To assess associations between changes in perceptions of the environment en route to work and changes in active commuting.
655 commuters in Cambridge, UK reported perceptions of their commuting route and past-week commuting trips in postal questionnaires in 2009 and 2010. Associations between changes in route perceptions and changes in time spent walking and cycling, proportion of car trips, and switching to or from the car on the commute were modelled using multivariable regression.
Changes in only a few perceptions were associated with changes in travel behaviour. Commuters who reported that it became less pleasant to walk recorded a 6% (95% CI: 1, 11) net increase in car trips and a 12 min/week (95% CI: − 1, − 24) net decrease in walking. Increases in the perceived danger of cycling or of crossing the road were also associated with increases in car trips. Increases in the perceived convenience of public transport (OR: 3.31, 95% CI: 1.27, 8.63) or safety of cycling (OR: 3.70, 95% CI: 1.44, 9.50) were associated with taking up alternatives to the car.
Interventions to improve the safety of routes and convenience of public transport may help promote active commuting and should be evaluated.
[Show abstract][Hide abstract] ABSTRACT: The planning profession has been advocated as an untapped resource for obesity prevention, but little is known about how planners view their roles and responsibilities in this area. This paper investigates the role of planners in the Healthy Towns programme in England, and explores the limits and potential for obesity prevention within planning policy and practice. Using a qualitative approach, 23 planning stakeholders were interviewed, identifying the potential for planning in public health, particularly the ‘health proofing’ of local planning policy. National and local governments should better align planning and health policies to support collaboration between planners and public health practitioners.
Health & Place 09/2014; 30:120–126. · 2.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
Active commuting may make an important contribution to population health. Accurate measures of these behaviours are required, but it is unknown how self-reported estimates compare to those derived from objective measures. We sought to develop methods for objectively deriving time spent in specific travel behaviours from a combination of locational and activity data, and to assess the convergent validity of two self-reported estimates.
In 2010 and 2011, a sub-sample of participants from the Commuting and Health in Cambridge study concurrently completed objective monitoring using combined heart rate and movement sensors and global positioning system devices and reported their past-week commuting in a questionnaire (modes used, and usual time spent walking and cycling per trip) and in a day-by-day diary (all modes and durations). Automated and manual approaches were used to objectively identify total time spent using active and motorised modes. Agreement between self-reported and objectively-derived times was assessed using Lin's concordance coefficients, Bland-Altman plots and signed-rank tests.
Compared to objective assessments, day-by-day diary estimates of time spent using active
modes on the commute were overestimated by a mean of 1.1 minutes/trip (95% limits of
agreement (LOA): −7.7 to 9.9, p < 0.001). The magnitude of overestimation was slightly
larger, but not significant (p = 0.247), when walking or cycling was used alone (mean: 2.4
minutes/trip, 95% LOA: −6.8 to 11.5). Total time spent on the commute was overestimated
by a mean of 1.9 minutes/trip (95% LOA: −15.3 to 19.0, p < 0.001). The mean differences
between self-reported usual time and objective estimates were −1.1 minutes/trip (95% LOA:
−8.7 to 6.4) for cycling and +2.4 minutes/trip (95% LOA: −10.9 to 15.7) for walking. Mean
differences between usual and daily estimates of time were <1 minute/trip for both walking
We developed a novel method of combining objective data to identify time spent using active and motorised modes, and total time spent commuting. Compared to objectively-derived times, self-reported times spent active commuting were slightly overestimated with wide LOA, suggesting that they should be used with caution to infer aggregate weekly quantities of activity on the commute at the individual level.
International Journal of Behavioral Nutrition and Physical Activity 09/2014; 11(1):116. · 3.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: No current validated survey instrument allows a comprehensive assessment of both physical activity and travel behaviours for use in interdisciplinary research on walking and cycling. This study reports on the test-retest reliability and validity of physical activity measures in the transport and physical activity questionnaire (TPAQ).
PLoS ONE 09/2014; 9(9):e107039. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Walking and cycling is widely assumed to substitute for at least some motorized travel and thereby reduce energy use and carbon dioxide (CO2) emissions. While the evidence suggests that a supportive built environment may be needed to promote walking and cycling, it is unclear whether and how interventions in the built environment that attract walkers and cyclists may reduce transport CO2 emissions. Our aim was therefore to evaluate the effects of providing new infrastructure for walking and cycling on CO2 emissions from motorized travel.
A cohort of 1849 adults completed questionnaires at baseline (2010) and one-year follow-up (2011), before and after the construction of new high-quality routes provided as part of the Sustrans Connect2 programme in three UK municipalities. A second cohort of 1510 adults completed questionnaires at baseline and two-year follow-up (2012). The participants reported their past-week travel behaviour and car characteristics from which CO2 emissions by mode and purpose were derived using methods described previously. A set of exposure measures of proximity to and use of the new routes were derived.
Overall transport CO2 emissions decreased slightly over the study period, consistent with a secular trend in the case study regions. As found previously the new infrastructure was well used at one- and two-year follow-up, and was associated with population-level increases in walking, cycling and physical activity at two-year follow-up. However, these effects did not translate into sizeable CO2 effects as neither living near the infrastructure nor using it predicted changes in CO2 emissions from motorized travel, either overall or disaggregated by journey purpose. This lack of a discernible effect on travel CO2 emissions are consistent with an interpretation that some of those living nearer the infrastructure may simply have changed where they walked or cycled, while others may have walked or cycled more but few, if any, may have substituted active for motorized modes of travel as a result of the interventions.
While the findings to date cannot exclude the possibility of small effects of the new routes on CO2 emissions, a more comprehensive approach of a higher ‘dosage’ of active travel promotion linked with policies targeted at mode shift away from private motorized transport (such as urban car restraint and parking pricing, car sharing/pooling for travel to work, integrating bike sharing into public transport system) may be needed to achieve the substantial CO2 savings needed to meet climate change mitigation and energy security goals.
Applied Energy 09/2014; 128:284–295. · 5.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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. (Am J Public Health. Published online ahead of print July 17, 2014: e1-e9. doi:10.2105/AJPH.2014.302059).
[Show abstract][Hide abstract] ABSTRACT: This paper explores how system-wide approaches to obesity prevention were 'theorised' and translated into practice in the 'Healthy Towns' programme implemented in nine areas in England. Semi-structured interviews with 20 informants, purposively selected to represent national and local programme development, management and delivery were undertaken. Results suggest that informants articulated a theoretical understanding of a system-wide approach to obesity prevention, but simplifying this complex task in the context of uncertainty over programme aims and objectives, and absence of a clear direction from the central government, resulted in local programmes relying on traditional multi-component approaches to programme delivery. The development of clear, practical guidance on implementation should form a central part of future system-wide approaches to obesity prevention.
Health & Place 06/2014; 29C:60-66. · 2.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Media content can increase awareness of, and shape interactions with, public health interventions. As part of a natural experimental evaluation of the travel, physical activity and health impacts of the Cambridgeshire Guided Busway, we analysed print and social media discourse and interview data to understand the nature of new transport infrastructure and how it was experienced.
BMC Public Health 05/2014; 14(1):482. · 2.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Introduction Economic appraisal of walking and cycling interventions in the physical environment is often conducted, but the health benefits are often overlooked. This study (www.iconnect.ac.uk) used the Health Economic Assessment Tools (HEAT) for walking and cycling to estimate the economic value of health benefits attributable to Connect2, a programme of constructing or improving 84 local walking and cycling routes around the UK.
Methods Average weekly times spent walking and cycling before and after the intervention were estimated from 563 adult survey respondents who reported using Connect2 infrastructure. Average weekly usage was derived using count data for 27 sites before and after the intervention. It was assumed that average changes in time spent, and counts of, walking and cycling applied across all Connect2 sites. Default HEAT input values were used for relative risk of mortality, value of a statistical life, and time frame for calculating mean annual benefit. The cost-benefit ratio was calculated using the overall cost of the programme (£170 million) and a 3.5% discount rate for future resource savings. The final model was based on a five year build-up for benefits, a two year build-up for uptake, and a 30 year assessment period.
Results Interim model outputs indicate benefit-cost ratios in a range (>4-1):1 as a result of increases in walking and cycling attributable to use of Connect2 infrastructure.
Discussion The findings will be compared with those for other interventions to promote walking and cycling. Future directions for estimating the health benefits will be discussed.
International Congress on Physical Activity and Public Health; 04/2014
[Show abstract][Hide abstract] ABSTRACT: Aim:
This study (www.iconnect.ac.uk) used the Health Economic Assessment Tools (HEAT) for walking and cycling to estimate the economic value of health benefits attributable to Connect2, a programme of constructing or improving 84 local walking and cycling routes around the UK.
Economic appraisal of walking and cycling interventions in the physical environment is often conducted, and it is usually the case that a new scheme or programme will only receive funding if projected costs are outweighed by the projected benefits. The economic impact of an intervention on factors including congestion and the environment are commonly assessed, however, consideration of the health benefits that emerge from such interventions are commonly overlooked.
Average weekly times spent walking and cycling before and after the intervention were estimated from 536 adult survey respondents who reported using Connect2 infrastructure. Average weekly usage before and after the intervention was derived from count data for 27 sites. It was assumed that average changes in time spent, and counts of, walking and cycling applied across all Connect2 sites. Default HEAT input values were used for relative risk of mortality, value of a statistical life, and time frame for calculating mean annual benefit. The benefit-cost ratio was calculated using the overall cost of the programme (£170 million) and a 3.5% discount rate for future resource savings. The final model was based on a five year build-up for benefits, a two year build-up for uptake, and a 30 year assessment period.
Interim model outputs indicate benefit-cost ratios in a range (>4-1):1 as a result of increases in walking and cycling attributable to use of Connect2 infrastructure.
Findings will be compared with those for other interventions to promote walking and cycling. Future directions for estimating the health benefits will be discussed.
South West Public Health Scientific Conference, Weston-super-Mare, UK; 02/2014
[Show abstract][Hide abstract] ABSTRACT: This paper explores how system-wide approaches to obesity prevention were ‘theorised’ and translated into practice in the ‘Healthy Towns’ programme implemented in nine areas in England. Semi-structured interviews with 20 informants, purposively selected to represent national and local programme development, management and delivery were undertaken. Results suggest that informants articulated a theoretical understanding of a system-wide approach to obesity prevention, but simplifying this complex task in the context of uncertainty over programme aims and objectives, and absence of a clear direction from the central government, resulted in local programmes relying on traditional multi-component approaches to programme delivery. The development of clear, practical guidance on implementation should form a central part of future system-wide approaches to obesity prevention.
Health & Place 01/2014; 29:60–66. · 2.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Accurate assessment tools are required for the surveillance of physical activity (PA) levels and the assessment of the effect of interventions. In addition, increasing awareness of PA is often used as the first step in pragmatic behavioural interventions, as discrepancies between the amount of activity an individual perceives they do and the amount actually undertaken may act as a barrier to change. Previous research has demonstrated differences in the amount of activity individuals report doing, compared to their level of physical activity when measured with an accelerometer. Understanding the characteristics of those whose PA level is ranked differently when measured with either self-report or accelerometry is important as it may inform the choice of instrument for future research. The aim of this project was to determine which individual characteristics are associated with differences between self-reported and accelerometer measured physical activity.
PLoS ONE 01/2014; 9(6):e99636. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The idea that behaviour can be influenced at population level by altering the environments within which people make choices (choice architecture) has gained traction in policy circles. However, empirical evidence to support this idea is limited, especially its application to changing health behaviour. We propose an evidence-based definition and typology of choice architecture interventions that have been implemented within small-scale micro-environments and evaluated for their effects on four key sets of health behaviours: diet, physical activity, alcohol and tobacco use.
We argue that the limitations of the evidence base are due not simply to an absence of evidence, but also to a prior lack of definitional and conceptual clarity concerning applications of choice architecture to public health intervention. This has hampered the potential for systematic assessment of existing evidence. By seeking to address this issue, we demonstrate how our definition and typology have enabled systematic identification and preliminary mapping of a large body of available evidence for the effects of choice architecture interventions. We discuss key implications for further primary research, evidence synthesis and conceptual development to support the design and evaluation of such interventions.
This conceptual groundwork provides a foundation for future research to investigate the effectiveness of choice architecture interventions within micro-environments for changing health behaviour. The approach we used may also serve as a template for mapping other under-explored fields of enquiry.
BMC Public Health 12/2013; 13(1):1218. · 2.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Physical activity patterns have been shown to change significantly across the transition to retirement. As most older adults approach retirement as part of a couple, a better understanding of how spousal pairs influence each other's physical activity behaviour in retirement may help inform more effective interventions to promote physical activity in older age. This qualitative study aimed to explore and describe how couples influence each other's physical activity behaviour in retirement.
A qualitative descriptive study that used purposive sampling to recruit seven spousal pairs with at least one partner of each pair recruited from the existing EPIC-Norfolk study cohort in the east of England, aged between 63 and 70 years and recently retired (within 2-6 years). Semi-structured interviews with couples were performed, audio-recorded, transcribed verbatim and analysed using data-driven content analysis.
Three themes emerged: spousal attitude towards physical activity, spouses' physical activity behaviour and spousal support. While spouses' attitudes towards an active retirement were concordant, attitudes towards regular exercise diverged, were acquired across the life course and were not altered in the transition to retirement. Shared participation in physical activity was rare and regular exercise was largely an individual and independent habit. Spousal support was perceived as important for initiation and maintenance of regular exercise.
Interventions should aim to create supportive spousal environments for physical activity in which spouses encourage each other to pursue their preferred forms of physical activity; should address gender-specific needs and preferences, such as chances for socialising and relaxation for women and opportunities for personal challenges for men; and rather than solely focusing on promoting structured exercise, should also encourage everyday physical activity such as walking for transport.
BMC Public Health 12/2013; 13(1):1197. · 2.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Retirement is associated with an increase in recreational physical activity but its impact on other domains of activity (at home, for transport) and sedentary behaviour, such as time spent watching television (TV) is unknown. We examined the association between retirement and changes in domain-specific and overall activity and TV viewing.
Data were derived from the population-based EPIC (European Prospective Investigation into Cancer)-Norfolk cohort. Physical activity and TV viewing time were self-reported at baseline (1997-2000) and follow-up 2 (2006-2007) by 3334 participants employed at baseline, of whom 785 (24%) were retired at follow-up 1 (2002-2006). Multivariable regression models were fitted to estimate the association between retirement and changes in physical activity and weekly TV viewing time.
Compared with continued employment, retirement was associated with a decline in overall activity (men: non-manual, -40.9 MET h/wk; manual, -49.6 MET h/wk; women: non-manual, -26.9 MET h/wk; manual, -31.6 MET h/wk; all p<0.001 (MET, metabolic equivalent of task)). Domain-specific activity declined for transport and occupational (p<0.001) and increased for recreational (p<0.02) and household (p≤0.002) activity. We observed significant interaction between retirement and social class in respect of overall and domain-specific activity apart from household activity. Retirement was associated with a mean increase in TV viewing time, with the largest increase among manual social classes (men: +3.9 h/wk; women: +2.8 h/wk; both p<0.001).
Interventions should aim to promote household and transport as well as recreational activity. Further research on the impact of retirement on sedentary behaviour is needed.
Journal of epidemiology and community health 12/2013; · 3.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective
To examine how adults use new local walking and cycling routes, and what characteristics predict use.
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.
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.
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.
Preventive Medicine 11/2013; 57(5):518–524. · 3.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Carbon dioxide (CO2) emissions from motorised travel are hypothesised to be associated with individual, household, spatial and other environmental factors. Little robust evidence exists on who contributes most (and least) to travel CO2 and, in particular, the factors influencing commuting, business, shopping and social travel CO2. This paper examines whether and how demographic, socio-economic and other personal and environmental characteristics are associated with land-based passenger transport and associated CO2 emissions. Primary data were collected from 3474 adults using a newly developed survey instrument in the iConnect study in the UK. The participants reported their past-week travel activity and vehicle characteristics from which CO2 emissions were derived using an adapted travel emissions profiling method. Multivariable linear and logistic regression analyses were used to examine what characteristics predicted higher CO2 emissions. CO2 emissions from motorised travel were distributed highly unequally, with the top fifth of participants producing more than two fifth of emissions. Car travel dominated overall CO2 emissions, making up 90% of the total. The strongest independent predictors of CO2 emissions were owning at least one car, being in full-time employment and having a home-work distance of more than 10 km. Income, education and tenure were also strong univariable predictors of CO2 emissions, but seemed to be further back on the causal pathway than having a car. Male gender, late-middle age, living in a rural area and having access to a bicycle also showed significant but weaker associations with emissions production. The findings may help inform the development of climate change mitigation policies for the transport sector. Targeting individuals and households with high car ownership, focussing on providing viable alternatives to commuting by car, and supporting planning and other policies that reduce commuting distances may provide an equitable and efficient approach to meeting carbon mitigation targets.