CFAS Geographic Data Manual - rationale and procedures to generate environmental data for the Cognitive Function and Ageing Studies (CFAS) II and Wales

This data manual is related to the Impact of the Environment and Air Pollution on Cognitive Health (EPOCH) study on the links between the built and natural environment on cognitive impairment and dementia. Dementia, a syndrome related to a decline in cognitive function and loss of functional ability, has been recognised to be a critical issue in ageing societies across the globe. The built environment - human-made infrastructures and facilities, such as street network and public transport - can play a key role in influencing health behaviours and prevention of obesity and non-communicable diseases, it is important to investigate the potential impact of the built environment on cognitive health in older people and further consider other related environmental characteristics, such as the natural environment (non-human made surroundings such as green and blue spaces) and pollution (air pollutants and noise). Recent studies have suggested that vibrant, high-density, destination-rich neighbourhood environments can provide opportunities for older residents to engage in physical, social and mental activities that benefit cognitive health.

This project integrated data on the neighbourhood built environment (dwelling density, street intersection density, land use, public transport and different types of services), natural environment (greenness, distance to parks and natural aquatic features), pollution (air pollutants and noise) and population-based cohort studies (UK: Cognitive Function and Ageing Study (CFAS) II, CFAS Wales. Advanced statistical methods such as generalised structural equation modelling, nonlinear structural equation mixture modelling and multistate modelling were used to examine hypotheses on the relationships between different neighbourhood environmental attributes and cognitive health measures and investigate the meditating effects of lifestyle behaviours (engagement in physical, social and mental activities) and the modifying effects of sociodemographic (sex, education and socioeconomic status).