Sudden Cardiac Arrest in New South Wales (Nsw), Australia: A Data Linkage Study

Sudden cardiac arrest (SCA) is a global health challenge. Routinely collected health data represents a potential source of data to identify SCA. Evaluate whether routinely collected health data can retrospectively identify community-based SCA (1-50 years) in NSW. Potential SCA cases (aged 1-50yrs; occurring in NSW; cardiac-related ICD-9/10/SNOMED codes) were identified by the Centre for Health Record Linkage (CHeReL) in the NSW Ambulance OHCA Register (OHCAR) and NSW Emergency Department Data Collection (EDDC). Probabilistic data linkage was undertaken between ambulance, hospital and mortality datasets. External causes were excluded at case identification in ambulance records. Cardiac aetiology was assigned where a cardiac diagnosis appeared in hospital admission or cause of death records. From 1.7 million linked records, 13,345 presumed SCA cases were identified; 54% had cardiac aetiology and 83% were fatal. Cardiac cases were older than non-cardiac cases (median 42 vs 37 years, p < 0.001) and more likely to be admitted to hospital (58% vs 7%, p < 0.001). Within cardiac cases, rhythm-related and structural diagnoses dominated in 1-11 year olds, while ischaemic disease dominated in 35-50 year olds. Older cardiac cases were more likely to die pre-hospital (adjusted OR 3.56, 95% CI 2.66-4.85, for 35-50 vs 1-11 years). Multi-source administrative data linkage identifies age-related patterns in SCA aetiology and clinical trajectory. Findings extrapolated nationally suggest approximately 370 cardiac SCA deaths per year in Australians aged 1 to 35, a substantial burden that could be tracked through routine data linkage.