ISBN: 978-1-4731-3093-7 Table 9: Characteristics of review question Population People with suspected heart failure in a community or outpatient setting. Target condition Heart failure Index test(s) NT-proBNP BNP Reference standard(s) A clinical diagnosis based on the opinion of at least one cardiologist, considering symptoms (potentially with some signs) and objective evidence of cardiac dysfunction (either structural or functional). Statistical measures Diagnostic accuracy of BNP and NT-proBNP: 2x2 tables Specificity Sensitivity PPV/NPV ROC curve or Area under Curve Study design Single gate studies (cohort/cross-sectional) 5.1.3 Review question: In people with suspected heart failure, what is the clinical and cost effectiveness of N-terminus pro-B-type natriuretic peptide (NT-proBNP) compared to B- type natriuretic peptide (BNP), when each is followed by the appropriate patient pathway, in order to improve patient outcomes? Table 10: PICO characteristics of review question Population People with suspected heart failure in a community or outpatient setting. Index diagnostic test + treatment NT-proBNP assay (at any reported threshold) Treatment/next step in pathway: Echocardiography Comparator index diagnostic tests + treatment BNP assay (at any reported threshold) Treatment/next step in pathway: Echocardiography Outcomes Efficacy outcomes: All-cause mortality Quality of life Unplanned hospitalisation Process outcomes: Number of people receiving echocardiography, i.e., including people who may not have needed it such as those with false positive results Repeat testing / additional testing Secondary accuracy outcomes: Sensitivity / specificity and other test accuracy measures Study design Systematic Review RCT 5.1.4 Clinical evidence A search was conducted for single gate studies assessing the diagnostic test accuracy of BNP or NT- proBNP to identify the presence of heart failure (as indicated by the reference standard) in people suspected of heart failure in a community or outpatient setting. A search was also conducted for diagnostic RCTs comparing outcomes in people tested with BNP versus NT-proBNP. 