Neighbourhood social cohesion, loneliness and multimorbidity: Evidence from a UK longitudinal panel study.

In the context of population ageing, multimorbidity is an increasingly prevalent public health issue that has a substantial impact on both individuals and healthcare systems. Alongside the literature looking at risk factors at the individual level, there is a growing body of research examining the role of neighbourhoods in the development of multimorbidity. However, most of this work has focused on physical features of place such as air pollution and green space, while social features of place have been largely overlooked. In this study, we therefore explored neighbourhood cohesion as a social neighbourhood characteristic that could influence multimorbidity risk. Additionally, we analysed how loneliness may help to explain any relationship between neighbourhood cohesion and multimorbidity, given the emergence of loneliness as an important risk factor for multimorbidity in individual-level studies. Using Understanding Society, a UK household longitudinal panel study of approximately 40,000 households, we conducted both multilevel cross-sectional and longitudinal analyses to model these relationships. We found that there is a substantial association between greater neighbourhood cohesion and lower multimorbidity risk (odds ratio (OR) for second most cohesive quintile versus least cohesive quintile = 0.75, p < .01), even after controlling for a wide range of socio-economic factors, health behaviours and physical features of place. This cross-sectional result was confirmed by longitudinal analysis of individuals with no health conditions at baseline who moved between neighbourhoods over a nine-year follow-up period. Movers who experienced a decrease in cohesion had greater odds of becoming multimorbid compared to movers who did not experience a decrease in cohesion (OR = 1.68, p = .057). Controlling for loneliness substantially attenuates the odds ratios for neighbourhood cohesion, and in a mediation analysis we found a significant indirect effect of neighbourhood cohesion on multimorbidity risk acting through loneliness, suggesting it is a plausible mechanism through which the social environment influences the development of multiple long-term health conditions.