Title: How effective is the Forestry Commission Scotland’s woodland improvement programme - ‘Woods In and Around Towns’ (WIAT) - at improving psychological wellbeing in deprived communities?
Funder: Chief Scientist Office (Scotland)

Abstract: Design Setting & Target Population:Following guidance from the MRC Population Health Sciences Research Network we will treat the WIAT intervention as a natural experiment. In partnership with FCS we will select 6 woodland sites within the Scottish Lowlands Forest District with associated communities that meet current WIAT inclusion criteria and are in the worst 30% of socio-economic deprivation in Scotland. Woodland sites will not have received investment or direct promotion within the last 2 years. Three intervention sites will receive the WIAT programme between 2012 and early 2015 three control sites matched on woodland and community characteristics will not. The intervention is in two stages: firstly it makes changes to the physical woodland environment designed to facilitate greater use; secondly it undertakes community engagement activities to advertise and promote woodland use. We expect the intervention to increase engagement and contact with the woodland leading to improvements in mental wellbeing reflected in lower PSS scores. The design draws on i) data from a population-level study in Denmark which measured associations between PSS and use of green space ii) our pilot evaluation of an earlier phase of WIAT focused on change in woodland visits.The design combines a repeat cross-sectional survey of individuals resident in intervention and control communities with three waves of data collection to assess health impacts and a longitudinal mixed-method study to track the environmental changes in woodlands and promotional activities which take place. For our quantitative study we will recruit adults from each of the study communities using a random sample of addresses within 1km of the woodland sites in each community. Our sampling frame will be the postcode address file.Intervention being evaluated:The intervention is guided by a woodland development plan created in partnership with the community. In stage 1 physical changes will be made to improve access to and within the woods (e.g. clearing shrubs creating paths and adding signage). In stage 2 activities designed to increase awareness and use of the woods by the local community (e.g. led-walk programmes leafleting and event days) will take place. The same programme will be applied across the 3 intervention sites though precise detail will be site-specific. WIAT projects involve an initial capital expenditure on environmental improvements of £10k - £100k and thereafter approximately £30k per year on management by wardens rangers and foresters as well as associated maintenance costs.Measurement of outcomes:The primary outcome will be a measure of mental wellbeing assessed using the Perceived Stress Scale (PSS) (35). It has has been used in studies relating natural environments and stress and is sensitive to change (34). Secondary outcomes as detailed in Section C3 will be measured using well-tested measures of woodland use and experience (3638 43-45) the Connectedness to Nature Scale (46) the NICE approved single-item physical activity assessment (47) General Health and Quality of Life (48) and social capital and cohesion (49).Changes in the nature and quality of the woodland sites will be monitored both independently (by experts surveyors using GIS) and with community-led audits. Community engagement interventions will be assessed through focus groups.Sample size:The literature suggests there are likely to be gender differences in the observed effects (25). Based on data from Stigsdotter et al (26) to detect a difference between intervention and control groups and identify gender differences in effect we need a total of n=1680 (420 men and women in each group). This would allow us to detect a difference in mean PSS scores of 1.2 with a common standard deviation of 6.2 based on a two-sided two-sample test with a 5% level of significance 80% power. We have allowed for a 25% additional sample to take into account any clustering effect. Thus our total sample size at each wave of survey will be 2100 (1050 per intervention or control group).We have not powered the study for further sub-group analysis. We will however consider other demographic and personal variables in analysis of the data which will also take account of the clustering of respondents within sites the sequential nature of the intervention and confounders such as life events. Sub group analyses will explore effects by age group baseline behavioural characteristics and stress levels.Planned analyses:As data will be collected via anonymous cross-sectional surveys we will not be able to link pre and post intervention results from the same individuals. To address the primary research question we will compare the outcome variables in the baseline with the stage 1 and stage 2 post-intervention periods for intervention and control sites. By undertaking three separate regressions one at each wave we will examine the effect of residence in intervention or control sites on PSS adjusting for differences on key confounding variables (sex age SES ethnicity education level employment status financial strain limiting illness and life events). To address secondary research questions we will adjust the models to control for level of community engagement with the woodlands; run new regressions with different outcomes of interest forming the dependent variable of an appropriate form of regression; examine the difference in coefficients between survey waves 1 and 2 and then 2 and 3; and run models stratified by gender and by distance from home postcode to site. Health economics analysis will initially take a cost-consequence approach costing each stage of the intervention and comparing those costs to the differences achieved in the intervention group over the control group on primary & secondary outcomes. In the second part the overall cost-consequence analysis from the first exercise will be extended to a more formal economic appraisal estimating the likely quality adjusted life year (QALY) benefits that might be expected from the programme. A Grounded Theory approach will be used in the qualitative work to explore how people experience and respond to the WIAT activities. Any unexpected positive or negative outcomes will be recorded both from the perspective of the communities and from the FCS staff and partners.Project timetables:Stage 1 of the intervention will occur in 2012/13 stage 2 in 2014/early 2015. The first wave survey will establish a baseline in 2012 with the two subsequent waves (in 2014 and 2015) undertaken at the same time of year to minimise the effects of seasonality and to fall at least 3 months after each intervention stage. Qualitative work will be ongoing at regular intervals throughout the project.


Research activity codes: 3.1 PRIMARY PREVENTION INTERVENTIONS TO MODIFY BEHAVIOURS OR PROMOTE WELL-BEING
Health categories: MENTAL HEALTH