Nichol G, Leroux B, Wang H et al. Trial of Continuous or Interrupted Chest Compressions during CPR. N Engl J Med. 2015 Nov 9. [Epub ahead of print].
CONCLUSIONS: In patients with out-of-hospital cardiac arrest, continuous chest compressions during CPR performed by EMS providers did not result in significantly higher rates of survival or favorable neurologic function than did interrupted chest compressions. (Funded by the National Heart, Lung, and Blood Institute and others; ROC CCC ClinicalTrials.gov number, NCT01372748 .). PMID: 26550795
Comment: It seems that perhaps depth of compressions is more important than continuous compressions. But it stills seems like it's best to stay on the chest as much as possible.