It is widely agreed that social factors are related to health outcomes: much research has served to establish correlations between classes of social factors on the one hand and classes of disease on the other hand. However, why and how social factors are an active part in the aetiology of disease development is something that is gaining attention only recently in the health sciences and in the medical humanities. In this paper, we advance the view that, just as biomarkers help trace the causal continuum from exposure to disease development at the biological level, sociomarkers ought to be introduced and studied in order to trace the social continuum from exposure to disease development. We explain how sociomarkers differ from social indicators and how they can be used in combination with biomarkers in order to reconstruct the mixed mechanisms of health and disease, namely mechanisms in which both biological and social factors have an active causal role.
The consequences of the COVID-19 pandemic are still working through health systems worldwide, and further reflections about the nature of health and disease, and about how to design and implement effective public health interventions are much needed. For numerous diseases and conditions, as well as for COVID-19, our knowledge base is rich. We know a lot about the biology of the disease, and we have plenty of statistics that relate health to socio-economic factors. In this paper, we argue that we need to add a third dimension to this knowledge base, namely a thorough description of the lifeworld of health and disease, in terms of the mixed biosocial mechanisms that operate in it. We present the concepts of lifeworld and of mixed mechanisms, and then illustrate how they can be operationalised and measured through mixed methodologies that combine qualitative and quantitative approaches. Finally, we explain the complementarity of our approach with the biological and statistical dimensions of health and disease for the design of public health interventions.