Effectiveness of dispatcher-assisted cardiopulmonary resuscitation in private home versus public locations for out-of-hospital cardiac arrest patients - A retrospective cohort study

Background: Dispatcher-assisted cardiopulmonary resuscitation (DACPR) significantly improves the survival of out-of-hospital cardiac arrest (OHCA) patients. However, the effectiveness of DACPR may vary depending on the location of the cardiac arrest. This study compares DACPR outcomes in private homes versus public places.

Methods: This retrospective cohort study included all OHCA incidents with emergency medical service (EMS) activation in Taichung City, Taiwan, from May 1, 2021, to April 30, 2022. Trained dispatch reviewers analyzed audio recordings of the included cases to extract DACPR indicators. The primary outcome was the number of successful chest compressions performed. Secondary outcomes included the proportion of OHCA recognition, call-to-chest compression time, call-to-OHCA recognition time, reasons for failure to identify OHCA, and reasons for failure to perform chest compressions or complete instructions. A subgroup analysis examined the caller-patient relationship in both locations.

Results: The study included 1,160 OHCA patients, with 1,009 cases occurring in private homes and 151 in public places. Patients in public places were younger (60 vs 75 years), more often male (81.5 % vs 59.9 %), and had a higher rate of witnessed collapse compared to those in private homes (40.4 % vs 26.7 %, p < 0.001). Chest compressions were less frequently administered in public places (41.1 % vs 65.5 %, adjusted odds ratio [aOR]: 0.48 [0.31 to 0.75]). Public place cases had a lower proportion of OHCA recognition (51.9 % vs 76.9 %) and longer call-to-OHCA recognition times (108 vs 79 s) than those in private homes. Callers in public places more often encountered hazardous environments or physical barriers (16.4 % vs 8.3 %) and refused to execute instructions (11.0 % vs 4.1 %), but faced fewer emotional or psychological obstacles (0 % vs 8.3 %). Family members in private homes had a higher proportion of chest compressions (67.1 % vs 53.8 %, aOR: 1.81 [1.15 to 2.83]) and shorter times to chest compression (160 s vs 171 s, adjusted beta: -30 s [-55.6 to -6.3]) compared to non-family members.

Conclusion: This study demonstrated reduced DACPR effectiveness in public places compared to private homes, potentially influenced by caller factors, environmental conditions, and the caller-patient relationship. Developing location-specific strategies is essential to enhance DACPR effectiveness.