The applied methodology, derived from the MONICA project, includes the identification of coronary and cerebrovascular current events through the record linkage of two information sources - death certificates (ISTAT) and hospital discharge records (HDR)- and the validation of a subsample of current events through the application of MONICA Project diagnostic criteria.
See study protocol and manual of operations (in italian).

Identification of current coronary events
To identify current fatal events, all death certificates reporting ICD-9 codes 410-414 (ischaemic heart diseases), 798-799 (sudden death), as underlying cause of death or ICD-9 codes 250 (diabetes), 401-404 (arterial hypertension), 420-429 (other forms of heart disease), 440-447 (diseases of the arteries and arterioles) as underlying cause of death associated with ICD-9 410-414 (ischaemic heart disease) in at least one of all secondary causes of death, are taken into account.
To identify non fatal events, hospital discharge records for patients alive at day 28, reporting ICD-9 codes 410-414 (ischaemic heart disease) as underlying or as any of the secondary discharge diagnoses, are taken into account.

Identification of current cerebrovascular events
To identify current fatal events, all death certificates, reporting ICD-9 codes 342 (hemiplegia), 430-434 (hemorragia and thrombosis), 436-438 (stroke and other undefined cerebrovascular diseases) as underlying cause of death or ICD-9 250 (diabetes), 401-404 (arterial hypertension), 427 (arrhythmia), 440 (atherosclerosis) as underlying cause of death associated with ICD-9 430-434, 436-438 in at least one of all secondary causes of death, are taken into account.
To identify non fatal events, hospital discharge records for patients alive at day 28, reporting ICD-9 codes 430-434 (hemorragia and thrombosis), 436-438 (stroke and other undefined cerebrovascular diseases) as underlying or as any of the secondary discharge diagnoses, are taken into account.

After validation, the events are classified using the MONICA project diagnostic categories, which represent the gold standard. This allows to calculate the positive predictive value of single codes recorded in the hospital discharge diagnoses and on the death certificates and to estimate for each single code the 'weighted' attack rate of the cause of discharge and death for non fatal and fatal events separately.