This guidance was developed in accordance with the methods outlined in the NICE guidelines manual, 2014 version.236 Sections 4.1 to 4.3 describe the process used to identify and review clinical evidence (summarised in Figure 3), sections 4.2 and 4.4 describe the process used to identify and review the health economic evidence, and section 4.5 describes the process used to develop recommendations. Figure 3: Step-by-step process of review of evidence in the guideline 4.1 Developing the review questions and outcomes Review questions were developed using a PICO framework (population, intervention, comparison and outcome) for intervention reviews; using a framework of population, index tests, reference standard and target condition for reviews of diagnostic test accuracy; using population, presence or absence of factors under investigation (for example prognostic factors) and outcomes for prognostic reviews; and using a framework of population, setting and context for qualitative reviews. This use of a framework guided the literature searching process, critical appraisal and synthesis of evidence, and facilitated the development of recommendations by the guideline committee. The review questions were drafted by the NGC technical team and refined and validated by the committee. The questions were based on the key clinical areas identified in the scope (appendix L). A total of 26 review questions were identified. Chronic Heart Failure Methods NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 Full literature searches, critical appraisals and evidence reviews were completed for all the specified review questions. Table 1: Review questions Chapter Type of review Review questions Outcomes 5 Diagnostic In people with suspected heart failure, what thresholds of pro-B-type natriuretic peptide (NT-proBNP) and B- type natriuretic peptide (BNP) are most accurate in identifying heart failure (as indicated by the reference standard)? 