Oving I, de Graaf C, Karlsson L, et al. - In view of previous research suggesting a decline in the proportion of a shockable initial rhythm (SIR) in out-of-hospital cardiac arrest (OHCA) during the last decades, researchers here examined if this decline is still ongoing. Further, they investigated the correlation between location of OHCA (residential vs public) and proportion of a SIR as initial rhythm. Using pooled data from the COSTA-group (Copenhagen, Oslo, Stockholm, Amsterdam), the proportion of patients with a SIR between 2006-2015 was calculated. Inclusion of a total of 19,054 OHCA cases was done. Findings revealed that the proportion of patients with a SIR in OHCAs has declined at a residential location. During the second half of the study period (2011-2015), this decline leveled off. No decline in SIR was observed over time in public locations.