Mapping the complex systems that connects the urban environment to cognitive decline in older adults: a group model building study

Background and aim: The number of people living with dementia and Mild Cognitive Impairment (MCI) is increasing. A supportive urban environment can prevent or delay the progress of cognitive decline. There is evidence for the existence of mechanistic pathways between the urban environment and cognitive decline, but the interrelations between these pathways are unclear. In this study, we aimed to map the mechanistic pathways by which urban environment factors impact cognitive decline in older adults. Methods: This study was part of the Supportive environments for Physical and social Activity, healthy ageing and CognitivE health (SPACE) project. A 2-day workshop with the SPACE investigators was conducted based on the Group Model Building (GMB) methodology. The workshop aimed to create a causal-loop diagram (CLD) that identifies established and potential urban environment, lifestyle, health, and physiological determinants of cognitive decline in older adults. A facilitation team guided the activities. The workshop was held online following appropriately adapted scripts. After the workshop, the modelling team reviewed the CLD to ensure that main potential causal pathways and mechanisms were captured. Results: During the workshop, 12 experts from 10 different disciplines identified 83 factors and 221 connections between them. After review, the CLD presented 50 factors and 154 connections. All factors were classified in 10 main groups: urban design, social environment, travel behaviours, urban design by-products, lifestyle, disease/physiology, mental health conditions, exogenous factors, and cognitive decline outcomes. The main output was a CLD of the complex system of how the urban environment can influence cognitive decline in older adults. Conclusions: The CLD detailed the plausible causal pathways between the urban environment and cognitive decline. Our findings suggested that GMB can engage experts and help them view problems through the lens of complex systems. Keywords: cognitive decline, urban environment, group model building