The following is a summary of “Validity of the “Roth score” for hypoxemia screening,” published in the April 2023 issue of Emergency Medicine by Hoz, et al.

Using a simple verbal test, the Roth score is a different method to gauge oxygen saturation. For a study, researchers sought to evaluate the validity of the Roth score (Spanish version) as a screening test for hypoxemia and to assess the agreement and consistency between pulse oximetry (SpO₂) and arterial blood gas test (SaO₂) measures.

The observational study was conducted in two hospital emergency departments. The study included adult patients who underwent arterial blood gas tests, with pulse oximetry values and Roth scores recorded in Spanish. The sensitivity and specificity of the Roth score were evaluated through receiver operating characteristic (ROC) curves and by calculating the area under the curve (AUC) for SpO₂, SaO₂, and arterial blood oxygen pressure (PaO₂). In addition, the agreement between SpO₂ and SaO₂ was measured through the intraclass correlation coefficient (ICC), and consistency between the two measures was calculated through the Bland-Altman method.

The ROC curve analysis of the Roth score for SaO₂ < 90%, ≤92%, and < 95% showed AUCs of 0.574, 0.462, and 0.543, respectively, for the highest number obtained, as well as AUCs of 0.403, 0.376, and 0.495, respectively, for the maximum time used. Similarly, the AUCs for PaO₂ ≤ 60, ≤70, and ≤80 mmHg were 0.534, 0.568, and 0.512, respectively, for the maximum number obtained, and AUCs of 0.521, 0.515, and 0.519, respectively, for the maximum time spent. The intraclass correlation coefficient (ICC) between SaO₂ and SpO₂ was 0.817 (P < 0.001), and the mean difference between the two measurements was −0.55.

The Roth score performed in Spanish was not a valid test for hypoxemia screening. However, there was good agreement and consistency between SaO₂ and SpO₂ measures.

Source: sciencedirect.com/science/article/abs/pii/S0735675723000396