In Reply Dr Olsen and colleagues raise the important issue of a potential confounding effect of therapeutic hypothermia. Encouraging the use of hypothermia after arriving in the hospital, as recommended in guidelines, was part of our intervention. The increase in hypothermia from 55.6% to 65.4% during the 4 years of the study was unlikely to have substantially contributed to the improved survival and to the association of bystander CPR and early defibrillation with survival.
Malta Hansen C, Jollis JG, Granger CB. Initial Interventions for Out-of-Hospital Cardiac Arrest—Reply. JAMA. 2015;314(22):2414. doi:10.1001/jama.2015.13206