Data Resource Profile: Linking electronic health and social records to study and lower health inequalities in cardiovascular diseases (BIG-HEART)

BIG-HEART cohort was established to study and lower health inequalities of cardiovascular disease, by linking a multidimensional and rich collection of Estonia's electronic health and social data. The dataset includes all individuals aged 36 and above who resided in Estonia in 2012 (N=770,323). Its complete population representation minimises sampling and healthy volunteer bias. Existing funding and permits will follow up for health outcomes annually until at least 2026, with future extensions possible. The dataset integrates all routinely collected individual-level primary and secondary care health data (including inpatient and outpatient attendance, diagnoses made, prescriptions issued and purchased), along with mortality data, plus comprehensive social data (including ethnicity, education, marital status, social benefits, unemployment history, land and business ownership) from eight national registries. This enables researchers to explore novel dimensions of social epidemiology, including unbiased measures of wealth, medication adherence and care quality, as well as the derivation and validation of equity-enhancing clinical risk prediction algorithms and large language models. Health and social data are linked using pseudonymised identifiers derived from national personal identification numbers, ensuring accuracy and privacy. The data are stored in the OMOP common data model, facilitating international collaboration. Collaboration inquiries can be directed to the BIG-HEART team at taavi.tillmann@ut.ee to explore potential opportunities.