Does perceived neighbourhood social cohesion moderate the effects of demographic changes on health?

Abstract Small-area characteristics changes over time may be associated with health. Various theories have been proposed to explain small-area effects on health, including those concerning social capital. The effect of small-area demographic changes on health are very little researched and hardly anything is known about their relationship with social cohesion. We use longitudinal data from the German Socio-Economic Panel linked to demographic measures at county level. We explore the association between 5-year changes in the proportion of over 65 and of 18-24 years-old and physical and mental health and the moderating effect of perceived neighbourhood social cohesion (SC) using random intercept models. Control variables include education, income, and relevant baseline measures. Included are all participants with a 6-year continuous exposure to their county of residence. The main outcomes are the physical and mental health components (PCS, MCS) of the SF-12. We included 21,239 persons up to 6 times in 399 counties. 5-year changes in the over 65, of 18-24 and measure of SC are associated to MCS and PCS. Significant interactions between the changes in over 65 and social cohesion are seen for MCS only in rural areas and some interactions are significant for PCS. For MCS there are no interactions between social cohesion and the changes in 18-24. Important interaction effects for PCS: for those exposed to a small decrease in 18-24, an increase in one unit of SC is associated with an increase of 1.71 (95% CI[1.38, 2.03]) PCS units. For those exposed to a large decrease this effect is lower by 0.88 PCS units. Exposition to some demographic changes have the effect to reduce the positive effects of perceived social cohesion on health. Thus, demographic changes appear to be health stressors. The evidence shown by this work need to be further developed by considering smaller scales but the evidence opens up a new range of possible intervention targets to reduce health inequalities. Key messages • County level demographic changes are associated with physical and mental health and certain exposition to changes reduce the positive effects of perceived neighbourhood social cohesion. • Social cohesion can be an intervention target to reduce small-area health inequalities, population changes can annulate positive effects. This must be accounted for in public health interventions.