 Dyspneic patients 65 years were enrolled in a randomized, controlled trial; hemodynamically unstable patients were excluded. BNP Biosite assay levels were measured prior to physician assessment with randomization in 1:1 ratio to either BNP 1 level reported or 2 level not reported. ED physicians made triage decisions guided by clinical judgment and nomogram to aid in interpretation of BNP level. Primary outcome was mean total hospital cost per subject. Secondary outcomes included admission rate, service assignment, discharge diagnosis and length of stay. Differences between groups were compared by t-test with bootstrap. Costs reflect 2005 constant dollars. 