Declining consciousness and/or cognition are expected when patients are near death. The RDOS performed well when tested with terminally ill patients who were at risk for respiratory distress, most of whom could not self-report dyspnea. The tool is sensitive to detect changes over time and measure response to treatment. The RDOS is simple to use; scoring takes less than 5 minutes. The RDOS has clinical and research utility to measure and trend respiratory distress and response to treatment.