Two new studies in the New England Journal of Medicine add to evidence that giving CPR with chest compressions alone is as effective or even better than the traditional method. That means those who got the compressions alone had just as good a chance at survival.
So, why would compression alone be most effective? One thought is that when someone without medical training stops hand compressions to do mouth-to-mouth it may take up too much time.
Earlier this year, ABC 7 talked with University of Chicago cardiologist Steven Archer about this theory.
"What we want people to do is 100 deep heart compressions and not stop," Archer said. "When you stop to give those breaths, all the profusion of the blood supply to heart and brain goes away."
What researchers also discovered is more bystanders are willing to attempt CPR if an emergency dispatchers gives them instructions.
The American Heart Association started recommending hands-only compression for those not trained in CPR a couple of years ago.