Introduction
This Part of the 2015 International Consensus on Cardiopul monary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC) Science With Treatment Recommendations (CoSTR) presents the consensus on science and treatment recommendations for adult basic life support (BLS) and automated external defibrillation (AED). After the publication of the 2010 CoSTR, the Adult BLS Task Force developed review questions in PICO (population, intervention, comparator, outcome) format.1 This resulted in the generation of 36 PICO questions for systematic reviews. The task force discussed the topics and then voted to prioritize the most important questions to be tackled in 2015. From the pool of 36 questions, 14 were rated low priority and were deferred from this round of evidence evaluation. Two new questions were submitted by task force members, and 1 was submitted via the public portal. Two of these (BLS 856 and BLS 891) were taken forward for evidence review. The third question (368: ForeignBody Airway Obstruction) was deferred after a preliminary review of the evidence failed to identify compelling evidence that would alter the treatment recommendations made when the topic was last reviewed in 2005. 2 Each task force performed a systematic review using detailed inclusion and exclusion criteria, based on the recommendations of the Institute of Medicine of the National Academies.3 With the assistance of information specialists, a detailed search for relevant articles was performed in each of 3 online databases (PubMed, Embase, and the Cochrane Library).Reviewers were unable to identify any relevant evidence for 3 questions (BLS 811, BLS 373, and BLS 348), and the evidence review was not completed in time for a further question (BLS 370). A revised PICO question was developed for the opioid question (BLS 891). The task force reviewed 23 PICO questions for the 2015 consensus on science and treatment recommendations, including BLS 811, BLS 373, and BLS 348. The PICO flow is summarized in Figure 1.Using the methodological approach proposed by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Working Group, 4 the reviewers for each question created a reconciled risk-of-bias assessment for each of the included studies, using state-of-the-art tools: Cochrane for randomized controlled trials (RCTs), 5 Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 for studies of diagnostic accuracy, 6 and GRADE for observational studies that inform both therapy and prognosis questions.7 GRADE evidence profile tables 8 were then created to facilitate an evaluation of the evidence in support of each of the critical and important outcomes. Critical outcomes were defined as neurologically favorable outcome (level 9), survival (level 8), and return of spontaneous circulation (ROSC; level 7). Given the heterogeneity of time points evaluated in the studies related to BLS/AED, time intervals were pooled across outcomes. For neurologic outcome and survival, we considered the outcomes at discharge,...