Background. The assessment and communication of disease risk that is personalised to the individual is widespread in healthcare contexts. Despite severa

Evidence regarding the association of the built environment with physical activity is influencing policy recommendations that advocate changing the built environment to increase population-level physical activity. However, to date there has been no rigorous appraisal of the quality of the evidence on the effects of changing the built environment. The aim of this review was to conduct a thorough quantitative appraisal of the risk of bias present in those natural experiments with the strongest experimental designs for assessing the causal effects of the built environment on physical activity. Eligible studies had to evaluate the effects of changing the built environment on physical activity, include at least one measurement before and one measurement of physical activity after changes in the environment, and have at least one intervention site and non-intervention comparison site. Given the large number of systematic reviews in this area, studies were identified from three exemplar systematic reviews; these were published in the past five years and were selected to provide a range of different built environment interventions. The risk of bias in these studies was analysed using the Cochrane Risk of Bias Assessment Tool: for Non-Randomized Studies of Interventions (ACROBAT-NRSI). Twelve eligible natural experiments were identified. Risk of bias assessments were conducted for each physical activity outcome from all studies, resulting in a total of fifteen outcomes being analysed. Intervention sites included parks, urban greenways/trails, bicycle lanes, paths, vacant lots, and a senior citizen’s centre. All outcomes had an overall critical (n = 12) or serious (n = 3) risk of bias. Domains with the highest risk of bias were confounding (due to inadequate control sites and poor control of confounding variables), measurement of outcomes, and selection of the reported result. The present review focused on the strongest natural experiments conducted to date. Given this, the failure of existing studies to adequately control for potential sources of bias highlights the need for more rigorous research to underpin policy recommendations for changing the built environment to increase physical activity. Suggestions are proposed for how future natural experiments in this area can be improved.

Green spaces are known to improve health and wellbeing via several mechanisms, such as by reducing stress and facilitating physical activity. However, little is known about the impact of the smaller green spaces typically found in urban environments on wellbeing, especially for older adults. This study investigated experiences in adults (5 males and 10 females) aged 60 years and over of small urban green spaces in a large UK city. Fifteen older adults were interviewed using semi-structured walk-along interviews and photo elicitation methods in Old Moat, Greater Manchester. Twelve of the participants lived in Old Moat at the time of the study, and the remaining three participants previously lived in Old Moat and were frequent visitors. Transcribed interviews were analyzed using Thematic Analysis. Smaller urban green spaces were perceived differently to large green spaces, and participants were more likely to use larger green spaces such as parks. The smaller green spaces were perceived as belonging to other people, which discouraged the older adults from using them. The older adults also emphasized the importance of taking care of small urban green spaces and preventing them from becoming overgrown. Urban planners should consider these factors, since they indicate that the size and type of urban green spaces may influence whether they improve health and wellbeing. Further research should investigate in more detail which types of urban green space are most conducive to facilitating physical activity and improving wellbeing.

Background: There are few robust natural experimental studies of improving urban green spaces on physical activity and wellbeing. The aim of this controlled natural experimental study was to examine the impact of green space improvements along an urban canal on canal usage, physical activity and two other wellbeing behaviours (social interactions and taking notice of the environment) among adults in Greater Manchester, UK. The intervention included resurfaced footpaths, removal of encroaching vegetation, improved entrances, new benches and signage. Methods: Two comparison sites were matched to the intervention site using a systematic five-step process, based on eight correlates of physical activity at the neighbourhood (e.g. population density) and site (e.g. lighting) levels. Outcomes were assessed using systematic observations at baseline, and 7, 12 and 24 months post-baseline. The primary outcome was the change in the number of people using the canal path from baseline to 12 months. Other outcomes were changes in physical activity levels (Sedentary, Walking, Vigorous), Connect and Take Notice behaviours. Data were analysed using multilevel mixed-effects negative binomial regression models, comparing outcomes in the intervention group with the matched comparison group, controlling for day, time of day and precipitation. A process evaluation assessed potential displacement of activity from a separate existing canal path using intercept surveys and observations. Results: The total number of people observed using the canal path at the intervention site increased more than the comparison group at 12 months post-baseline (IRR 2.10, 95% CI 1.79–2.48); there were similar observed increases at 7 and 24 months post-baseline. There was some evidence that the intervention brought about increases in walking and vigorous physical activity, social interactions, and people taking notice of the environment. The process evaluation suggested that there was some displacement of activity, but the intervention also encouraged existing users to use the canal more often. Conclusions: Urban canals are promising settings for interventions to encourage green space usage and potentially increase physical activity and other wellbeing behaviours. Interventions that improve access to green corridors along canals and provide separate routes for different types of physical activities may be particularly effective and warrant further research. Study protocol: Study protocol published in Open Science Framework in July 2018 before the first follow-up data collection finished (https://osf.io/zcm7v). Date of registration: 28 June 2018.

Creating or improving urban green space has the potential to be an effective, sustainable and far-reaching way to increase physical activity and improve other aspects of wellbeing in the population. However, there is a dearth of well-conducted natural experimental studies examining the causal effect of changing urban green space on physical activity and wellbeing. This is especially true in older adults and in the United Kingdom. This paper describes a natural experimental study to evaluate the effect of four small-scale urban street greening interventions on older adults’ physical activity and wellbeing over a 1-year period, relative to eight matched comparison sites. All sites are located in deprived urban neighbourhoods in Greater Manchester, United Kingdom. Components of the interventions include tree and flower planting, and artificial tree decorations. Eight unimproved comparison sites were selected based on a systematic process of matching using several known objective and subjective environmental correlates of physical activity in older adults. The outcome measures are physical activity and two other behavioural indicators of wellbeing (Connect: connecting with other people; and Take Notice: taking notice of the environment), collected using a newly developed observation tool. The primary outcome is Take Notice behaviour due to largest effects on this behaviour being anticipated from improvements in the aesthetic quality of green space at the intervention sites. Baseline data collection occurred in September 2017 before the interventions were installed in November 2017. Follow-up data collection will be repeated in February/ March 2018 (6 months) and September 2018 (12 months). The present study permits a rare opportunity to evaluate the causal effects of small-scale changes in urban green space in an understudied population and setting. Although the interventions are expected to have small effects on the outcomes, the present study contributes to developing natural experiment methodology in this field by addressing key methodological weaknesses causing high risk of bias in previous natural experimental studies. Key improvements to reduce risk of bias in the present study are rigorous matching of multiple comparison sites and appropriate statistical control of key confounders. Retrospectively registered with study ID NCT03575923 . Date of registration: 3 July 2018.

Direct observation of behaviour offers an unobtrusive method of assessing physical activity in urban spaces, which reduces biases associated with self-report. However, there are no existing observation tools that: (1) assess other behaviours that are important for people’s wellbeing beyond physical activity; (2) are suitable for urban spaces that typically have lower numbers of users (e.g. amenity green spaces) or that people pass through (e.g. green corridors); and (3) have been validated in Europe. MOHAWk (Method for Observing pHysical Activity and Wellbeing) is a new observation tool for assessing three levels of physical activity (Sedentary, Walking, Vigorous) and two other evidence-based wellbeing behaviours (Connect: social interactions; Take Notice: taking notice of the environment) in urban spaces. Across three studies, we provide evidence that MOHAWk is reliable and valid from 156 hours of observation by six observers in five urban spaces in the UK. MOHAWk can be used in policy or practice (e.g. by local authorities or developers), or in more formal institutional based research projects. This new tool is an inexpensive and easy-to-use method of generating wellbeing impact evidence in relation to the urban physical or social environment. A manual providing detailed instruction on how to use MOHAWk is provided.