Wei Y, Pek PP, Doble B, et al. - In order to determine the strategy that maximizes survival upon hospital discharge or 30-days post out-of-hospital cardiac arrest (OHCA) in Singapore for fixed investments of S$1, S$5, or S$10 million, researchers performed a comparison of four strategies: (1) no further investment; (2) decreasing response time via leasing of more ambulances; (3) improving number of people trained in cardiopulmonary resuscitation (CPR); and (4) automated external defibrillators (AED). They used Singapore’s 2010–2015 OHCA registry data to ascertain the effect of ambulance response time, bystander CPR and AED on survival. With no additional investment, survival was 4.03%. Given a given budget of S$1M, survival changes to 4.03%, 4.04%, and 4.44% in correlation to investments in ambulances, CPR training and AEDs, respectively with generation of 0, 2 and 102 additional life-years saved respectively. Saving of 509 or 886 additional life years is expected, given a budget of S$5M or S$10M, investing in an additional 10,000 or 20,000 AEDs respectively. When the budget was increased to ≥ S$5M for investment in ambulances and CPR training, the strategies attained a saturation effect whereby improvement in survival was marginal. These findings suggest that the most gain in survival would be achieved by investing in AEDs.