Neighbourhood safety and area deprivation modify the associations between parkland and psychological distress in Sydney, Australia

Background: The aim of this study was to investigate how perceived neighbourhood safety and area deprivation influenced the relationship between parklands and mental health. Methods. Information about psychological distress, perceptions of safety, demographic and socio-economic background at the individual level was extracted from New South Wales Population Health Survey. The proportion of a postcode that was parkland was used as a proxy measure for access to parklands and was calculated for each individual. Generalized Estimating Equations logistic regression analyses were performed to account for correlation between participants within postcodes, and with controls for socio-demographic characteristics and socio-economic status at the area level. Results: In areas where the residents reported perceiving their neighbourhood to be "safe" and controlling for area levels of socio-economic deprivation, there were no statistically significant associations between the proportion of parkland and high or very high psychological distress. In the most disadvantaged neighbourhoods which were perceived as unsafe by residents, those with greater proportions of parkland, over 20%, there was greater psychological distress, this association was statistically significant (20-40% parkland: OR=2.27, 95% CI=1.45-3.55; >40% parkland: OR=2.53, 95% CI=1.53-4.19). Conclusion: Our study indicates that perceptions of neighbourhood safety and area deprivation were statistically significant effect modifiers of the association between parkland and psychological distress.