Benedict W. Wheeler

Would You Be Happier Living in a Greener Urban Area? A Fixed-Effects Analysis of Panel Data:

Urbanization is a potential threat to mental health and well-being. Cross-sectional evidence suggests that living closer to urban green spaces, such as parks, is associated with lower mental distress. However, earlier research was unable to control for time-invariant heterogeneity (e.g., personality) and focused on indicators of poor psychological health. The current research advances the field by using panel data from over 10,000 individuals to explore the relation between urban green space and well-being (indexed by ratings of life satisfaction) and between urban green space and mental distress (indexed by General Health Questionnaire scores) for the same people over time. Controlling for individual and regional covariates, we found that, on average, individuals have both lower mental distress and higher well-being when living in urban areas with more green space. Although effects at the individual level were small, the potential cumulative benefit at the community level highlights the importance of policies to protect and promote urban green spaces for well-being.

Patterns of GPS measured time outdoors after school and objective physical activity in English children: the PEACH project

BackgroundObservational studies have shown a positive association between time outdoors and physical activity in children. Time outdoors may be a feasible intervention target to increase the physical activity of youth, but methods are required to accurately measure time spent outdoors in a range of locations and over a sustained period. The Global Positioning System (GPS) provides precise location data and can be used to identify when an individual is outdoors. The aim of this study was to investigate whether GPS data recorded outdoors were associated with objectively measured physical activity.MethodsParticipants were 1010 children (11.0 ± 0.4 years) recruited from 23 urban primary schools in South West England, measured between September 2006 and July 2008. Physical activity was measured by accelerometry (Actigraph GT1M) and children wore a GPS receiver (Garmin Foretrex 201) after school on four weekdays to record time outdoors. Accelerometer and GPS data were recorded at 10 second epochs and were combined to describe patterns of physical activity when both a GPS and accelerometer record were present (outdoors) and when there was accelerometer data only (indoors). ANOVA was used to investigate gender and seasonal differences in the patterns of outdoor and indoor physical activity, and linear regression was used to examine the cross-sectional associations between GPS-measured time outdoors and physical activity.ResultsGPS-measured time outdoors was a significant independent predictor of childrens physical activity after adjustment for potential confounding factors. Physical activity was more than 2.5 fold higher outdoors than indoors (1345.8 ± 907.3 vs 508.9 ± 282.9 counts per minute; F = 783.2, p < .001). Overall, children recorded 41.7 ± 46.1 minutes outdoors between 3.30 pm and 8.30 pm, with more time spent outdoors in the summer months (p < .001). There was no gender difference in time spent outdoors. Physical activity outdoors was higher in the summer than the winter (p < .001), whilst there was no seasonal variation in physical activity indoors.ConclusionsDuration of GPS recording is positively associated with objectively measured physical activity and is sensitive to seasonal differences. Minute by minute patterning of GPS and physical activity data is feasible and may be a useful tool to investigate environmental influences on childrens physical activity and to identify opportunities for intervention.

Mapping the walk to school using accelerometry combined with a global positioning system.

BACKGROUND Walking to school is associated with higher levels of physical activity, but the contribution of the journey itself to physical activity before school is unknown. PURPOSE This study combined accelerometer and GPS data to investigate the level and location of physical activity in children walking to school. METHODS Participants were 137 children (aged 11.3 + or - 0.3 years) from London, England, measured in June-July 2006. Physical activity was measured by accelerometry, and location was determined with a GPS receiver. Travel mode was self-reported. Accelerometer and GPS data were time-matched to provide activity level and location for each 10-second epoch where both were available. Journeys were mapped in a GIS. RESULTS Mean accelerometer counts per minute before school (8:00 am to 9:00 am) were 43% higher in those who walked to school than those traveling by car (878.8 + or - 387.6 vs 608.7 + or - 264.1 counts per minute [cpm], p<0.001). Eleven percent (4.5 minutes) of daily moderate to vigorous physical activity (MVPA) occurred in this hour, with walkers recording 2.1 minutes more than car travelers (p = 0.004). Children followed direct routes between home and the school playground. Total activity during the walk to school was twice that in the playground (2131.3 + or - 1170.7 vs 1089.7 + or - 938.6 cpm, p<0.001), with the journey contributing three times as much MVPA as time in the playground. CONCLUSIONS Our results provide evidence that the journey to school is purposeful and contributes to higher total physical activity and MVPA in children. Combining accelerometer and GPS data may aid our understanding of the environmental context of physical activity.

Environmental equity, air quality, socioeconomic status, and respiratory health: a linkage analysis of routine data from the Health Survey for England

Study objective: To assess relations between socioeconomic status and local air quality, and combined effects on respiratory health, in the context of environmental and health inequality. Design: Data on people taking part in the Health Survey for England were attributed with a small area index of air pollution using annual mean concentrations of nitrogen dioxide, sulphur dioxide, benzene, and particulates (PM10). Regression models were used to measure associations between social class, air quality, forced expiratory volume in one second (FEV1), and self reported asthma. Participants: Participants aged 16–79 in the Health Survey for England 1995, 1996, and 1997. Main results: Urban lower social class households were more likely to be located in areas of poor air quality, but the association in rural areas was, if anything reversed. Low social class and poor air quality were independently associated with decreased lung function (FEV1), but not asthma prevalence, after adjustment for a number of potential confounders. Social class effects were not attenuated by adjustment for air quality. In men, a differential effect of air pollution on FEV1 was found, with its effect in social classes III to V about double that in social classes I and II (p value for interaction = 0.04). This effect modification was not seen for women. Conclusions: Further evidence of environmental inequity in the UK is provided. The association between FEV1 and local air quality is of similar magnitude to that with social class, and the adverse effects of air pollution seem to be greater in men in lower social classes.

Does living by the coast improve health and wellbeing

It is often assumed that spending time by the coast leads to better health and wellbeing, but there is strikingly little evidence regarding specific effects or mechanisms to support such a view. We analysed small-area census data for the population of England, which indicate that good health is more prevalent the closer one lives to the coast. We also found that, consistent with similar analyses of greenspace accessibility, the positive effects of coastal proximity may be greater amongst more socio-economically deprived communities. We hypothesise that these effects may be due to opportunities for stress reduction and increased physical activity.

Contribution of the school journey to daily physical activity in children aged 11-12 years.

BACKGROUND Active travel is a possible method to increase physical activity in children, but the precise contribution of walking to school to daily physical activity is unclear. PURPOSE To combine accelerometer and GPS data to quantify moderate-to-vigorous physical activity (MVPA) on the walk to and from school in relation to overall daily levels. METHODS Participants were 141 children aged 11-12 years from the PEACH Project (Personal and Environmental Associated with Childrens Health) in Bristol, England, measured between 2008 and 2009. Eighty-four children met the inclusion criteria and were included in the final analysis. Accelerometers measured physical activity, GPS receivers recorded location, and mode of travel was self-reported. Data were analyzed between April and October 2011. Combined accelerometer and GPS data were mapped in a GIS. Minutes of MVPA were compared for school journeys taking place between 8:00 AM and 9:00 AM and between 3:00 PM and 5:00 PM and in relation to whole-day levels. RESULTS Physical activity levels during journeys to and from school were highly similar, and contributed 22.2 minutes (33.7%) of total daily MVPA. In addition, MVPA on the journey did not differ between boys and girls, but because girls have lower levels of daily physical activity than boys, the journey contributed a greater proportion of their daily MVPA (35.6% vs 31.3%). CONCLUSIONS The journey to and from school is a significant contributor to MVPA in children aged 11-12 years. Combining GPS and accelerometer data within a GIS is a useful approach to quantifying specific journeys.

Geography of suicide in Taiwan: Spatial patterning and socioeconomic correlates

In industrialised Western nations suicide rates tend to be high in inner city areas and socially fragmented neighbourhoods. Few studies have investigated spatial variations in suicide in non-Western settings. We estimated smoothed standardised mortality ratios (1999-2007) for suicide for each of the 358 Taiwanese districts (median population aged 15+: 27,000) and investigated their associations with area characteristics using Bayesian hierarchical models. The geographic distribution of suicide was similar in men and women; young people showed the greatest spatial variation in rates. Rates were highest in East Taiwan, a mostly mountainous rural area. There was no evidence of above average rates in large cities. Spatial patterns of method-specific suicide rates varied markedly, with solids/liquids poisonings showing the greatest geographic variation and hangings the least. Factors most strongly associated with area suicide rates were median household income, population density and lone-parent households. Spatial patterning of suicide in Taiwan differed from that observed in Western nations. Suicide prevention strategies should take into account unique local patterns.

What can global positioning systems tell us about the contribution of different types of urban greenspace to children’s physical activity?

Urban greenspace is hypothesised to be an important location for physical activity in children, but their actual use of the resource to be active is not well known. In this study, global positioning systems (GPS) and accelerometers were used to measure activity within green environments for 902 English children aged 11-12. We summarised activity intensities in different types of greenspace on weekday evenings, weekend days and by season. Around half of outdoor moderate-vigorous activity took place in greenspace at the weekend and use was consistent across seasons. The findings suggest the importance of certain types of greenspace to childrens physical activity.

The population impact on incidence of suicide and non-fatal self harm of regulatory action against the use of selective serotonin reuptake inhibitors in under 18s in the United Kingdom : ecological study

Objective To investigate the population impact on the incidence of suicide and non-fatal self harm of regulatory action in 2003 to restrict the use of selective serotonin reuptake inhibitors (SSRIs) in under 18s. Design Ecological time series study. Setting United Kingdom. Populations Young people in the UK aged 12-19 years (prescribing trends), in England and Wales aged 12-17 years (mortality), and in England aged 12-17 years (hospital admissions). Main outcome measures Deaths from suicide and hospital admissions for self harm. Results Antidepressant prescribing doubled between 1999 and 2003 but fell to the 1999 level between 2004 and 2005. These large changes in prescribing did not seem to be associated with temporal trends in suicide or self harm. In the years 1993 to 2005 the annual percentage reduction for suicide among 12-17 year olds was −3.9% (95% confidence interval −6.2% to −1.5%) in males and −3.0% (−6.6% to 0.6%) in females, with no indication of a substantial change in this rate of decrease during that period. Similarly, hospital admission rates for self harm in the years 1999 to 2005 indicated an annual percentage increase for males of 1.1% (−0.5% to 2.7%) and for females of 5.7% (3.6% to 7.8%), again with no statistical evidence of a change in rate after the regulatory action. Conclusions The noticeable reduction in prescribing of antidepressants since regulatory action in 2003 to restrict the use of SSRIs in under 18s does not seem to have been associated with changes in suicidal behaviour in young people. Specifically, these data for England do not indicate that reductions in antidepressant use have led to an increase in suicidal behaviour.

The Evolution of the Epidemic of Charcoal-Burning Suicide in Taiwan: A Spatial and Temporal Analysis

Shu-Sen Chang and colleagues describe the epidemiology of an epidemic of suicide by charcoal burning in Taiwan and discuss possible reasons for its spread.