Balan P, Hsi B, Thangam M, et al. - As for predicting mortality post-arrest, current methods require data unavailable at the time of initial medical contact, researchers sought to create as well as validate a risk prediction model for patients experiencing out-of-hospital cardiac arrest (OHCA) who achieved return of spontaneous circulation which relies only on objective information routinely obtained at first medical contact. Via performing a retrospective evaluation of 14,892 OHCA patients in a large metropolitan cardiac arrest registry, they identified 3,952 patients who had usable data; of these patients, 2,635 formed a derivation cohort and 1,317 formed a verification cohort. The final Cardiac Arrest Survival Score (CASS) was created including age > 75 years (odds ratio [OR] = 1.61), unwitnessed arrest (OR = 1.95), home arrest (OR = 1.28), absence of bystander CPR (OR = 1.35), and non-shockable initial rhythm (OR = 3.81). Mortality in OHCA patients could be accurately predicted using CASS. Only binary, objective clinical data routinely obtained at first medical contact are used by the model. More patients could be identified via early risk stratification in whom timely and aggressive invasive management may improve outcomes.