Both of which met the threshold set by the committee. A further single study of high Chronic Heart Failure Diagnosing heart failure quality (n=206) reported a high sensitivity of 96 (90-99) at a threshold of 166pg/ml which again met the threshold set by the committee. At several thresholds, there was sufficient evidence to pool the diagnostic accuracy data. At the thresholds of 125pg/ml, 280pg/ml and 400pg/ml (3 studies; n=826) the sensitivities were 96 (72-100), 89 (41-99) and 79 (42-96) respectively. For the very high rule in threshold of 2000pg/ml the committee placed an emphasis on specificity. A single high quality study (n=200) reported a specificity of 100 (97-100) at this diagnostic threshold which met the threshold set by the committee for possible recommendation. Economic One cost-utility anlaysis found the most cost effective diagnostic strategy for referring people with signs and symptoms of heart failure for echocardiography is to refer those with a history of myocardial infacrtion straight to echocardiography, and otherwise using an NT-proBNP threshold of 400pg/ml. This was compared to the MICE clinical decision rule (upper and lower thresholds), echo all, NT-proBNP threshold 125pg/ml and do nothing. It was cost effective compared to the do nothing strategy (ICER: 4,400 per QALY gained). This was assessed as diretly applicable with potentially serious limitations. An original cost-utility analysis found that 400pg/ml is the most effective NT-proBNP threshold to use for referring people presenting with signs and symptoms of heart failure for echocardiography compared to 280pg/ml, 125pg/ml and referring all patients straight for echocardiography. It was cost effective compared to referring all patients for echocardiography (ICER: 6,076 per QALY gained). This was assessed as directly applicable with potentially serious limitations. 