Table 2

Hierarchical data mining procedure to assess natural causes of death in the death certificate to define one cause per death, and other related conditions

ConditionHierarchical definition
1Mention of COVID-19, coronavirus: considered as ‘COVID-19’ (suspected or confirmed).
 1.1Mention of ACS/infarction, associated with COVID-19, coronavirus: considered as ‘ACS with COVID-19’.
 1.2Mention of stroke (ischaemic or haemorrhagic), associated with COVID-19: considered as ‘stroke with COVID-19’.
2Mention of severe acute respiratory syndrome: considered as ‘SARS’.
3Mention of ACS/infarction not associated with COVID-19, coronavirus: considered as ‘ACS without COVID-19’ (ACS).
4Mention of stroke (ischaemic of haemorrhagic) not associated with COVID-19, considered ‘stroke without COVID-19’ (stroke).
5Mention of pneumonia associated with non-cardiovascular causes (excluding those listed above): considered as ‘pneumonia’.
6Mention of an undetermined cause, sudden death or cardiorespiratory arrest, associated with arterial hypertension, diabetes mellitus, pulmonary embolism, heart failure, dilated cardiomyopathy, pulmonary oedema, atrioventricular block, cardiac arrhythmia, supraventricular tachycardia, ventricular tachycardia, fibrillation atrial, bradycardia: considered ‘unreported cause associated with cardiovascular disease’.
7Mention of ‘sudden death’: considered ‘sudden death’.
8Mention of cardiogenic shock, associated with ischaemic disease, was considered ‘cardiogenic shock associated with ischaemic disease’.
9Mention of sepsis as the only reported cause: considered as ‘sepsis’.
10Mention of respiratory failure as the only reported cause: considered as ‘respiratory failure’.
11Mention of indeterminate cause as the only reported cause: considered as ‘indeterminate cause’.
12Death not classified under any of the previous conditions: considered as ‘other cause’.