This directed acyclic graph is used to inform the estimation of the total causal effect of pre-existing cardiovascular disease on cancer treatment receipt using population-based cancer registry records in Northern Ireland. Northern Ireland Cancer Registry (NICR) has collected cancer data for NI residents since 1993, using pathology reports, hospital records, and death registrations. Cancer Information Officers verify diagnoses following international standards, and can also use additional data from radiotherapy, chemotherapy systems and multidisciplinary team discussions records. All patients aged 18 or older who were diagnosed with cancer, excluding non-melanoma skin cancer, for the first time in NI between 2009 and …