Abstract 77: Regional Variation in the Incidence of OHCA and Bystander CPR
Background: Bystander CPR is a significant predictor of survival among people who have an out of hospital cardiac arrest (OHCA). We aimed to identify areas with a high incidence of OHCA and low rates of bystander CPR, across a population of 5.7 million in the State of Victoria (Australia).
Methods: We extracted adult data for presumed cardiac OHCAs from the Victorian Ambulance Cardiac Arrest Registry for 2008 to 2011. We calculated the incidence of OHCA in Victorian Local Government Areas (LGAs) using yearly population data from the Australian Bureau of Statistics, and bystander CPR rates for each LGA.
For the incidence rate (log-transformed) and the bystander CPR rate we calculated the standard score (Z-score) using the mean and standard deviation among all LGAs, and standardized by dividing the standard deviation by the square root of the population in each LGA.
Results: Over the study period there were 22,990 OHCA attended. The mean annual incidence rate of OHCA among LGAs was 91.9 cases per 100,000 population (IQR: 71.5-106.5). The rate of CPR for bystander witnessed OHCAs was 59.6%, the median value among LGAs was 58.6% (IQR: 51.3%-70.6%).
The figure shows significant variation in the rate of bystander CPR across regions. The bubble size indicates the relative volume of cases. The LGA highlighted in green represents Melbourne Central Business District, where arrests are more likely to occur in public places. The box outlined in the lower right indicates those LGAs with low bystander CPR and high incidence of OHCA. This LGA highlighted in yellow was ranked first in the state in an index of socio-economic disadvantage for 2011.
Conclusions: Our data supports reports of regional variation in OHCA incidence and bystander CPR rates -which in our case occured even across a large metropolitan city and among bystander witnessed OHCAs. Visualising bystander CPR rates in the context of OHCA incidence and volume identifies those regions where there is the greatest capacity to improve survival.
Author Disclosures: L. Straney: None. J. Bray: None. J. Finn: None. K. Smith: None.
- © 2014 by American Heart Association, Inc.