Ms Emily Nehme1,2, A/Prof David Anderson1,2,3, Mr Ross Salathiel1,2, Mr Anthony Carlyon1, Prof Dion Stub1,2,3, Prof Peter Cameron2,3, Dr Andrew Wilson4, Dr Sile Smith5, Prof John McNeil2, Dr Ziad Nehme1,2
1Ambulance Victoria, Blackburn North, Australia, 2Monash University, Melbourne, Australia, 3The Alfred Hospital, Melbourne , Australia, 4St Vincent’s Heart Centre, Melbourne , Australia, 5Royal Children’s Hospital, Melbourne, Australia
Background: The Victorian Ambulance Cardiac Arrest Registry is uniquely placed to describe trends in out-of-hospital cardiac arrest (OHCA) characteristics and survival outcomes over a 20-year period.
Methods: We performed a retrospective cohort study of OHCAs in Victoria between 01/01/2003 and 31/12/2022. Emergency Medical Service (EMS)-witnessed OHCA were excluded. Annual crude and age-standardised incidence rates were calculated. Multivariable logistic regression was used to estimate annual odds of survival to hospital discharge.
Results: 102,592 OHCAs were included. Annual age-standardised incidence remained stable over time (2003: 89.1 vs. 2022: 91.2 OHCA per 100,000 population, p-trend=0.5). For patients receiving a resuscitation attempt by EMS, rates of bystander cardiopulmonary resuscitation (CPR) (2003-04: 40.3% vs. 2021-22: 72.2%) and defibrillation (2003-04: 0.9% vs. 2021-22: 16.1%) increased considerably. After adjustment, the odds of survival to hospital discharge within the Ustein comparator group (witnessed, initially shockable OHCAs) were three times greater in 2022 than 20 years prior (Adjusted Odds Ratio (AOR)=3.08 [95% Confidence Interval (CI) 2.22,4.27]). However, relative to 2012, only 2018 (AOR=1.37 [95%CI 1.04,1.80]) and 2019 (AOR=1.68 [95%CI 1.28,2.21]) were associated with significant improvements in survival. The COVID-19 pandemic was associated with a 37% reduction in the odds of survival. The proportion of 12-month survivors reporting full health-related quality of life was 38.5%, however this fluctuated annually.
Conclusion: Utstein survival increased 3-fold over the 20-year period, and this was associated with increased rates of bystander CPR and public access defibrillation. The COVID-19 pandemic was associated with a reduction in survival, and new strategies are needed to improve outcomes.
Biography:
Emily Nehme is Ambulance Victoria’s Research Governance Manager and a Biostatistician. Emily has published >100 peer-reviewed manuscripts and was awarded an NHMRC post-graduate scholarship for her PhD program. Professionally, she oversees 120 active research projects and leads a linked data initiative between AV, ED and admissions data in Victoria.