Accuracy of Respiratory Distress Observational Scale (RDOS) in the emergency department

Dyspnea is a personal perception of breathing discomfort. The patient self-reported numerical rating scale (NRS) from 1 to 10 is an accurate tool for assessing dyspnea severity following the definition of dyspnea. The Respiratory Distress Observation Scale (RDOS) is an alternative dyspnea severity measurement for patients with impaired communication abilities. This study aims to evaluate the accuracy of RDOS and determine the optimal cutoff point in the emergency department (ED). This cross-sectional observational study was nested in a previous study investigating the inter-rater reliability of RDOS in the EDs of two academic hospitals. The participants were emergency physicians who were the first responders to adult patients presenting with dyspnea. The patient reports NRS, while the physician assesses RDOS using the record forms separately. The study excluded patients with impaired communication. A total of 122 patients and 44 emergency physicians rated RDOS. The overall severity of dyspnea was rated by the total median self-reported NRS as 7 (5, 8), and the total median RDOS as 5 (3, 7). For the diagnostic performance, the highest AUC is 0.783 (95% CI 0.684-0.883) if the RDOS cutoff point is ≥ 4, distinguishing mild from moderate-to-severe dyspnea. This cutoff point yields a sensitivity of 65.7% and a specificity of 90.9%. The RDOS is a potential observational tool in assessing dyspnea severity for emergency patients who are able to communicate. The RDOS ≥ 4 cutoff points differentiate mild from moderate-to-severe dyspnea.