Long-term outcomes of adult out-of-hospital cardiac arrest in Queensland, Australia (2002–2014): incidence and temporal trends

OBJECTIVE: To describe annual incidence and temporal trends (2002-2014) in incidence of long-term outcomes of adult out-of-hospital cardiac arrest (OHCA) of presumed cardiac aetiology attended by Queensland Ambulance Service (QAS) paramedics, by age, gender, geographical remoteness and socioeconomic status (SES). METHODS: This is a retrospective cohort study. Cases were identified using the QAS OHCA Registry and were linked with entries in the Queensland Hospital Admitted Patient Data Collection and the Queensland Registrar General Death Registry. Population data were obtained from the Australian Bureau of Statistics to calculate incidence. Inclusion criteria were adult (18+ years) residents of Queensland who suffered OHCA of presumed cardiac aetiology and survived to hospital admission. Analyses were undertaken by three mutually exclusive outcomes: (1) survival to less than 30 days (Surv<30 days); (2) survival from 30 to 364 days (Surv30-364 days); and (3) survival to 365 days or more (Surv365+ days). Incidence rates were calculated for each year by gender, age, remoteness and SES. Temporal trends were analysed. RESULTS: Over the 13 years there were 4393 cases for analyses. The incidence of total admitted events (9.72-10.13; p<0.01), Surv30-364 days (0.18-0.42; p<0.05) and Surv365+ days (1.94-4.02; p<0.001) increased significantly over time; no trends were observed for Surv<30 days. An increase in Surv365+ days over time was observed in all remoteness categories and most SES categories. CONCLUSION: Evidence suggests that implemented strategies to improve outcomes from OHCA have been successful and penetrated groups living in more remote locations and the lower socioeconomic groups. These populations still require focus. Ongoing reporting of long-term outcomes from OHCA should be undertaken using population-based incidence.