The authors reply

We thank Blakely et al. (1) for their observations. We welcome their stance that researchers conducting instrumental variable (IV)–fixed-effects (FE) analysis should be wary of potential violations of the exclusion restriction—in our study (2), the assumption that eligibility for the free bus pass only impacts cognitive function through the effect on public transportation use. The exclusion restriction is essentially untestable and must be supported by strong arguments. We argue that Blakely et al.’s concerns do not offer convincing evidence to conclude that the difference in magnitude between our FE estimates and our IV-FE estimates is due to an exclusion restriction violation

Are neighbourhood social capital and availability of sports facilities related to sports participation among Dutch adolescents?

<p>Abstract</p> <p>Background</p> <p>The aim of this study is to explore whether availability of sports facilities, parks, and neighbourhood social capital (NSC) and their interaction are associated with leisure time sports participation among Dutch adolescents.</p> <p>Methods</p> <p>Cross-sectional analyses were conducted on complete data from the last wave of the YouRAction evaluation trial. Adolescents (n = 852) completed a questionnaire asking for sports participation, perceived NSC and demographics. Ecometric methods were used to aggregate perceived NSC to zip code level. Availability of sports facilities and parks was assessed by means of geographic information systems within the zip-code area and within a 1600 meter buffer. Multilevel logistic regression analyses, with neighborhood and individual as levels, were conducted to examine associations between physical and social environmental factors and leisure time sports participation. Simple slopes analysis was conducted to decompose interaction effects.</p> <p>Results</p> <p>NSC was significantly associated with sports participation (OR: 3.51 (95%CI: 1.18;10.41)) after adjustment for potential confounders. Availability of sports facilities and availability of parks were not associated with sports participation. A significant interaction between NSC and density of parks within the neighbourhood area (OR: 1.22 (90%CI: 1.01;1.34)) was found. Decomposition of the interaction term showed that adolescents were most likely to engage in leisure time sports when both availability of parks and NSC were highest.</p> <p>Conclusions</p> <p>The results of this study indicate that leisure time sports participation is associated with levels of NSC, but not with availability of parks or sports facilities. In addition, NSC and availability of parks in the zip code area interacted in such a way that leisure time sports participation is most likely among adolescents living in zip code areas with higher levels of NSC, and higher availability of parks. Hence, availability of parks appears only to be important for leisure time sports participation when NSC is high.</p

Public Transportation Use and Cognitive Function in Older Age: A Quasiexperimental Evaluation of the Free Bus Pass Policy in the United Kingdom

In this quasiexperimental study, we examined whether the introduction of an age-friendly transportation policy- free bus passes for older adults-increased public transport use and in turn affected cognitive function among older people in England. Data came from 7 waves (2002-2014) of the English Longitudinal Study of Ageing (n = 17,953), which measured total cognitive function, memory, executive function, and processing speed before and after the bus pass was introduced in 2006. The analytical strategy was an instrumental-variable approach with fixed effects, which made use of the age-eligibility criteria for free bus passes and addressed bias due to reverse causality, measurement error, and time-invariant confounding. Eligibility for the bus pass was associated with a 7% increase in public transport use. The increase in public transportation use was associated with a 0.346 (95% confidence interval: 0.017, 0.674) increase in the total cognitive function z score and with a 0.546 (95% confidence interval: 0.111, 0.982) increase in memory z score. Free bus passes were associated with an increase in public transport use and, in turn, benefits to cognitive function in older age. Public transport use might promote cognitive health through encouraging intellectually, socially, and physically active lifestyles. Transport policies could serve as public health tools to promote cognitive health in aging populations

Socioeconomic inequalities in smoking and drinking in adolescence:social network dynamics

BackgroundNetwork-based interventions have the potential to prevent socioeconomic inequalities in health behaviors but require a good understanding of the underlying social network mechanisms. We investigated whether (1) adolescents selected friends with a similar socioeconomic status (SES), (2) smoking and alcohol consumption spread in networks, and (3) the exclusion of non-smokers or non-drinkers differed between SES groups.MethodsWe applied Stochastic Actor Oriented Models to the complete social network data (“Wired into Each Other” data) of 253 adolescents in eight Hungarian secondary school classes over three waves between 2010 and 2013. SES was measured based on entitlement to an income-tested regular child protection benefit.ResultsHigh SES adolescents were most likely to form friendships with peers from their own SES group (odds ratio [OR] = 1.1, 95% Confidence Interval [CI] = 1.0-1.1). Adolescents adjusted their smoking behavior (OR = 24.0, 95% CI 1.3-454.9) but not their alcohol consumption (OR = 1.6, 95% CI 0.6-4.4) to emulate the behavior of their friends. Smokers did not differ from non-smokers in the likelihood of receiving a friendship nomination (OR = 1.0, 95% CI 0.9-1.1), regardless of their SES. Alcohol consumers received significantly more friendship nominations than non-consumers (OR = 1.2, 95% CI 1.0-1.3), but this association was not significantly different according to SES.ConclusionsSocioeconomic inequalities in health behaviors were driven by preferences to form friendships within their own SES group and the spread of smoking and alcohol consumption in the network. These inequalities were not amplified by SES differences in encouraging smoking or drinking.Main messages: In three waves of observations in a Hungarian adolescent cohort, the study found social network effects for inequalities in smoking and alcohol consumption

Hosting elite sport events to target recreational sport participation: an interrupted time series analysis

Increasing sport participation by hosting elite sport events is a muchdebated policy. This study evaluated the effect of hosting elite sport events on sport participation against the background of a shift in focus towards targeting recreational sport participation. We included 10 international elite sport events organised between 2000 and 2017 in the city of Rotterdam, the Netherlands. Sport-specific participation in the pastyear was obtained from abiannual cross-sectional survey. Per event, interrupted time series analyses were employed using 3 pre- and post-event measures. Data were summarised by means of random-effects metaanalyses. We tested for group differences to evaluate if events organised in the period with amore explicit aim to target recreational sport participation, and associated policies, had alarger impact. Three events concerning cycling, table tennis and gymnastics were followed by an increase in sport-specific participation 1-year after the event was organised, whereas the korfball event was followed by adecrease. The pooled effect of the 10 events did not show any change in sport-specific participation (0.2%-point (95% CI: −0.3; 0.8)). Significant group differences by period were found. More recent events targeting sport participation were followed by an increase in sport-specific participation (1.1%-point (95% CI: 0.0; 2.1)), but not for other events (−0.3%-point (95% CI: −0.6; 0.1)). No group differences were found for the number of visitors and location. Hosting elite sport events that explicitly target sport participation may increase sport participation among citizens. Longitudinal data following individuals over time are needed to support this finding