Climate change increases the frequency and intensity of heatwaves, amplifying heat-related health risks in cities worldwide. Inequities in heat vulnerability arise from disparities in heat exposure, built and natural environments and population attributes that impact heat sensitivity, and socio-economic determinants of adaptive capability. A lack of internationally consistent and accessible heat vulnerability metrics creates barriers to assessing inequities and benchmarking urban heat vulnerability between cities worldwide. To address this need, we developed the Global Urban Heat Vulnerability Index (GUHVI), applicable to cities worldwide, using open data to identify spatial inequities in heat vulnerability at the neighbourhood scale. Built from an Australia-specific heat vulnerability index, the evidence-informed framework developed for the GUHVI evaluates heat exposure, heat sensitivity and adaptive capability to holistically assess heat vulnerability. Quantitative validation for eight Australian cities demonstrated strengths of the GUHVI in spatial resolution and assessment coverage of the grid-based framework. Qualitative validation for nine diverse cities internationally was performed in collaboration with local subject matter experts with knowledge of each city context. The GUHVI addresses critical gaps in existing methods by enabling systematic and comparable measurement of heat vulnerability in diverse cities internationally. Available through our customizable open-source global indicator software, the GUHVI provides evidence on modifiable risk factors of urban heat vulnerability, to inform targeted adaptation strategies that promote climate resilience and reduce health impacts from heat.

Active travel (AT) has gained increasing attention as a way of addressing low levels of physical activity. However, little is known regarding the relationship between income and AT. The aim of this study was to investigate characteristics associated with undertaking AT in an adult population and by low-and high-income groups. Data collected from the Physical Activity and the Rejuvenation of Connswater (PARC) study in 2017 were used. Participants were categorised into socio-economic groups according to their weekly household income, and were categorised as par-ticipating in ‘no’ AT or ‘some’ AT and ‘sufficient’ AT. Multivariable logistic regression explored characteristics associated with AT in the full cohort, and the low-and high-income groups sepa-rately. Variables associated with AT in the low-income group were body mass index (BMI), physical activity self-efficacy, marital status, long term illness, difficulty walking and housing tenure. For the high-income group, BMI, marital status, housing tenure and education were associated with AT. For both income groups, there were consistent positive associations with the action/maintenance phase of the stage of change model across all AT categories. The findings suggest that population sub-groups may benefit from targeted initiatives to support engagement in AT and prevent further widening of inequalities.

Background: Evidence for the health benefits of urban green space tends to stem from small, short-term quasi-experimental or cross-sectional observational research, whilst evidence from intervention studies is sparse. The development of an urban greenway (9 km running along 3 rivers) in Northern Ireland provided the opportunity to conduct a natural experiment. This study investigated the public health impact of the urban greenway on a range of physical activity, health, wellbeing, social, and perceptions of the environment outcomes. Methods: A repeated cross-sectional household survey of adult residents (aged ≥16 years) who lived ≤1-mile radius of the greenway (intervention sample) and > 1-mile radius of the greenway (control sample) was conducted pre (2010/2011) and 6-months post implementation (2016/2017). We assessed changes in outcomes pre- and post-intervention follow-up including physical activity behaviour (primary outcome measure: Global Physical Activity Questionnaire), quality of life, mental wellbeing, social capital and perceptions of the built environment. Linear regression was used to calculate the mean difference between post-intervention and baseline measures adjusting for age, season, education, car ownership and deprivation. Multi-level models were fitted using a random intercept at the super output area (smallest geographical unit) to account for clustering within areas. The analyses were stratified by distance from the greenway and deprivation. We assessed change in the social patterning of outcomes over time using an ordered logit to make model-based outcome predictions across strata. Results: The mean ages of intervention samples were 50.3 (SD 18.9) years at baseline (n = 1037) and 51.7 (SD 19.1) years at follow-up (n = 968). Post-intervention, 65% (adjusted OR 0.60, 95% CI 0.35 to 1.00) of residents who lived closest to the greenway (i.e., ≤400 m) and 60% (adjusted OR, 0.64 95% CI 0.41 to 0.99) who lived furthest from the greenway (i.e.,≥1200 m) met the physical activity guidelines - 68% of the intervention sample met the physical activity guidelines before the intervention. Residents in the most deprived quintiles had a similar reduction in physical activity behaviour as residents in less deprived quintiles. Quality of life at follow-up compared to baseline declined and this decline was significantly less than in the control area (adjusted differences in mean EQ5D: -11.0 (95% CI − 14.5 to − 7.4); − 30.5 (95% CI − 37.9 to − 23.2). Significant change in mental wellbeing was not observed despite improvements in some indicators of social capital. Positive perceptions of the local environment in relation to its attractiveness, traffic and safety increased. Conclusions: Our findings illustrate the major challenge of evaluating complex urban interventions and the difficulty of capturing and measuring the network of potential variables that influence or hinder meaningful outcomes. The results indicate at this stage no intervention effect for improvements in population-level physical activity behaviour or mental wellbeing. However, they show some modest improvements for secondary outcomes including positive perceptions of the environment and social capital constructs. The public health impact of urban greenways may take a longer period of time to be realised and there is a need to improve evaluation methodology that captures the complex systems nature of urban regeneration.