Riva G, et al. - In this nationwide study, researchers analyzed changes in the rate and type of cardiopulmonary resuscitation (CPR) performed in out-of-hospital cardiac arrest (OHCA) cases before the arrival of emergency medical services (EMS) over three consecutive guideline periods (2000-2005, 2006-2010, and 2011-2017) in correlation to 30-day survival. The study sample consisted of 30,445 patients who had CPR for OHCAs. Eligible patients were classified as receivers of no CPR (NO-CPR), standard CPR (S-CPR), or chest compression–only cardiopulmonary resuscitation (CO-CPR) before EMS arrival. Findings revealed an approximately two-fold higher rate of CPR before EMS arrival and a concomitant six-fold higher rate of CO-CPR over time. Compared with NO-CPR, doubled survival rates were noted in relation to any type of CPR. CO-CPR was related to higher CPR rates and overall survival and, hence, should be considered as an option in future CPR guidelines.