Analysis and optimization of location of automated external defibrillators in Pittsburgh

Background: Out-of-hospital cardiac arrests (OHCA) is one of the leading causes of mortality in the United States. According to the AHA in 2013, 400,000 people experienced OHCA and the mortality is as high as 9 out of every 10 cases. Using Automated External Defibrillator (AED) is the only effective treatments for restoring a regular heart rhythm during a sudden cardiac arrest. The aim of this study is to elaborate the importance of using AEDs in decreasing mortality due to OHCA in the city of Pittsburgh, PA. Hypothesis: 1) The AED density increases with the density of cardiac arrest. 2) Census tracts with Low socioeconomic status (Below the poverty line) is associated with lower number of AEDs in Allegheny County. 3) Census tracts with higher number of individuals over age 60 is associated with lower number of AEDs in Allegheny County Methods: AEDs were located through the HeartMap, which is a multicity community improvement project. A total of 979 AEDs were identified. Cardiac Arrest case data were obtained from the Resuscitation Outcome Consortium (ROC). During 2010 – 2014, a total of 3188 cardiac arrests were determined. We used the “American community survey”, 2013 to obtain below poverty line income levels and percentage of people above age 60 for each census tract. Maps were created to demonstrate the distribution of AEDs, OHCA, age demographics, and socio economic status. Association between AEDs and OHCA / demographics / socioeconomic status were explored at the census tract level in Allegheny County. Data was analyzed using geospatial plotting, an analysis tool created in MATLAB. We linearly regressed AED density and cardiac arrests density to find an association between the two, and found an inverse relationship between the two variables (P = 0.027, coeff – 0.003). There was no statistically significant difference between AEDs density and socioeconomic status or population over age 60 (P > 0.05). Result: As cardiac arrest density increased, AED density decreased. Census tracts with low socioeconomic status and individuals over age 60 were not significantly associated with lower number of AEDs. Preventing mortality due to OHCA with a help of an AED is an important step that needs to be taken from a public health stand point.