Association between greenness, walkability, and multimorbidity in a cohort of British Columbians

This study examined the association between built environment features (specifically, greenness and walkability) and multimorbidity prevalence and the mediating effect of health behaviours (diet, body weight, physical activity, smoking, and alcohol consumption) in this association. An analysis was conducted of 27 268 participants aged 34–73 years from a population-based longitudinal cohort, the British Columbia Generations Project. Multimorbidity was defined as the presence of two or more chronic conditions from 17 self-reported diseases. Built environment data (greenness and walkability) were provided by the Canadian Urban Environmental Health Research Consortium (CANUE). Multivariable logistic regression models were used to examine the association between greenness and walkability and multimorbidity. Path analysis, employing a structural equation modelling approach, was used to explore the mediating effect of health behaviours. A total of 35% of participants had multimorbidity. There was no significant association between greenness and multimorbidity prevalence. The least walkable neighbourhoods (quintile 1) had higher odds of multimorbidity (OR = 1.50, 95% CI:1.34, 1.70) than the most walkable (quintile 5) neighbourhoods, after adjusting for confounders. Smoking mediated 20% of the walkability-multimorbidity association, indicating that walkable neighbourhoods might have lower multimorbidity prevalence due to less smoking. Built environment design, such as increasing walkability, is an emerging multimorbidity prevention measure.