Researchers looked at 4,415 adult cardiac arrests outside of hospitals in Arizona from 2005 to 2009 during the campaign.
The rate of bystanders attempting any type of CPR increased from 28 percent in 2005 to 40 percent in 2009. Bystanders were more likely to use hands-only CPR over traditional CPR as time went on.
And victims who got hands-only were more likely to survive: 113 of 849 victims (13 percent) who received the hands-only method survived, compared to 52 of 666 victims (about 8 percent) who received conventional CPR.