Subjective and objective indicators of neighbourhood safety and physical activity among UK adolescents

The health benefits of regular physical activity in adolescence are well-documented and many health-related behaviours are established in adolescence. The neighbourhood environment is a key setting for physical activity for adolescents and feeling unsafe in their neighbourhood may be a potential barrier to physical activity.This study aimed to examine associations between neighbourhood safety and physical activity using objective and subjective measures for both.Participants (n = 10,913) came from the Millennium Cohort Study, a nationally representative UK longitudinal birth cohort. Linear regression and Zero Inflated Poisson models were used to examine associations between subjective and objective indicators of safety (self-reported safety, Index of Multiple Deprivation crime, Reported Crime Incidence) and physical activity (self-reported weekly and device-measured physical activity).Adolescents who feel unsafe in their neighbourhood, or who live in areas with high IMD crime or violent crime rates report 0.29 (95% CI -0.49, -0.09) 0.32 (95% CI -0.47, -0.16) and 0.20 (95% CI -0.39, -0.20) fewer days of physical activity, respectively. No associations were found between Reported Crime Incidence and either objective or subjective measures of physical activity.This study demonstrates varying associations between subjective safety and objective crime with physical activity levels in adolescence, highlighting the complexities around subjective and objective measurements and their associations with health outcomes.