Abstract 335: The Potential of Using Passenger Flow to Guide AED Deployment at Train Stations

Background: According to earlier guidelines, many countries have deployed AEDs at train stations to improve survival after OHCA. However, train stations are heterogeneous in size and traffic, and the association between passenger flow and OHCA incidence remains unexplored. Hypothesis: At train stations, OHCA risk is associated with passenger flow, and patients have better outcomes compared to other public OHCAs. Aims: To guide a strategic deployment of AEDs, we aimed to investigate the incidence of OHCA and its association with passenger flow, as well as outcomes after OHCA at train stations nationwide. Methods: We included non-EMS witnessed OHCAs from the Danish Cardiac Arrest Registry (2016-2020). Data on stations were obtained from The Danish State Railways and Metro Company . Using QGIS stations were geocoded as a 100-meter radius from the center of the station, and stations where buffers were not possible due to size or structure polygons, were drawn. Stations were divided into groups based on the number of passengers/day: 1 (0-500), 2 (500-5,000), 3 (5,000-10,000), and 4 (>10,000), respectively.We used Fisher’s exact test to compare outcomes. We analyzed the incidence rate’s association with passenger flow and the risk ratio using Poisson regression of rates. Results: Train stations accounted for 102 (2.3%) of all 4,467 public OHCAs. The incidence rate (IR) and risk ratio (RR) for OHCA were for group 1: IR = 0.02 OHCA/station/year, RR = 1.0 (ref); group 2: IR = 0.07, RR = 4.1 (95%CI 2.3-7.3); group 3: IR = 0.25, RR = 12.7 (95%CI 6.2-25.9); and group 4: IR = 0.34, RR = 16.3 (95%CI 8.6-30.9).OHCAs at train stations were more likely defibrillated by bystanders (28.4% (95% CI 0.20-0.38) vs. 20.4% (95%CI 0.19-0.22), p-value = 0.063), more patients achieved ROSC (56.8% (95% CI 0.47-0.67) vs. 43.8% (95% CI 0.43-0.46), p-value = 0.011) and had a higher survival (45.1% (95% CI 0.35-0.55) vs. 27.0% (95% CI 0.26 - 0.28), p-value <0.001) compared to other public OHCAs. Conclusion: The incidence of OHCA at trains station was directly associated with passenger flow, with the busiest stations having a 16-fold higher risk of OHCA than the lowest, making passenger flow an important indicator for AED deployment. OHCAs at train stations had better outcomes than other public OHCAs.