The committee agreed that the critical outcomes were all-cause mortality, quality of life and unplanned hospitalisations. In addition, a number of process outcomes were considered important, these were number of people receiving echocardiography, i.e., including people who may not have needed it such as those with false positive results, and the need for repeat or additional testing. Test accuracy measures would also be extracted if reported in clinical effectiveness studies. In the reviews focussing on the diagnostic accuracy of NT-proBNP and BNP at different thresholds in each population, sensitivity was considered the most critical outcome. This is because failing to diagnose people who have heart failure may delay the initiation of treatment and increase the risk of unplanned hospitalisations and mortality prior to an eventual diagnosis. A minimum threshold of 95% sensitivity was set for recommending the test. Chronic Heart Failure Diagnosing heart failure NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 Specificity was also considered important in order to avoid unnecessary referrals for echocardiography and specialist clinical assessment where heart failure was highly unlikely. Other accuracy statistics considered important were positive and negative predictive values and area under the curve (AUC), which provides an overall summary of the test performance. No evidence was identified for any of the clinical effectiveness outcomes for any of the reviews, including the process outcomes. Quality of the clinical evidence No RCTs were identified that compared a diagnostic strategy using NT- proBNP with a diagnostic strategy using BNP to establish the impact on patient outcomes, in any of the patient populations. General suspected heart failure population Eight diagnostic accuracy studies were included that evaluated the diagnostic accuracy of NT-proBNP and/or BNP at diagnosing heart failure in the general suspected heart failure population. 