Background
This study aimed to determine whether a new dispatcher-assisted basic life support (DA-BLS) training program is associated with improved quality in CPR training. 

Methods
This was a prospective, clustered randomized clinical trial conducted in three district health community centers in Seoul. Intervention was a new DA-BLS training program and control was standard BLS program. Primary outcome was total number of chest compressions during the course of the training. The secondary outcome was an average compression depth and tertiary outcomes were other CPR quality parameters and post-training survey results. Difference in difference (DID) analysis was performed to show whether CPR quality parameters were improved from baseline to last session during the training period.

Results 
A total of 152 classes (1,929 trainees) were included in the final analysis. The intervention group showed significantly higher average number of chest compression compared with the control group (604 vs. 431). Overall, trainees in the intervention group showed better CPR quality indicators compared with control group throughout the course. However, both groups showed decreased in CPR performances from baseline to last session in all CPR quality parameters. DID analysis showed less changes in all of the quality parameters from baseline to last session in intervention group (p<0.01 for all). In the post-training survey, disagreement rate in voluntariness about bystander CPR was significant lower in the intervention group.

Conclusion
The new DA-BLS training program provided more number of chest compressions and resulted overall better CPR quality parameters.

4 - The Effectiveness of a New Dispatcher-Assisted Bystander CPR Program on Quality Improvement in CPR Training: A cluster randomized controlled trial