Dysphagia Risk Score two (DRS2): Development and validation of a rapid screening card for dysphagia in patients with stroke

Background- Each year approximately 15 million people around the world are affected by stroke, about six million die, while five million suffer from severe disabilities. Oropharyngeal dysphagia (OD) is a frequent comorbidity, affecting between 37% and 78% of stroke patients. The early assessment of dysphagia has a significant influence on the patient’s health, on hospitalization times and ultimately on the costs of care for the stroke patient. Nonetheless, there is a gap between recommendations and clinical reality. The objective of this study is the validation of a screening tool, Dysphagia Risk Score 2 (DRS2), consisting of 8 items, whose administration takes about 120 seconds. Methods- The study involved 1006 patients (499 female and 507 male), aged between 15 and 101 years (mean age 70), evaluated with the DRS2 within 24/48 hours of admission to the Stroke Unit of the A.O. San Camillo-Forlanini in Rome and the San Giovanni Battista Hospital. Patients were enrolled in order of admission. To validate the scale, out of those 1006 patients, a random sample of 168 subjects (100 male and 68 female, mean age 71) also underwent an examination with a fiberoptic endoscopic evaluation of swallowing (FEES) during the same diagnostic session. To evaluate the reproducibility of the DRS2 score, a random sample of 35 of the total 1006 patients was evaluated simultaneously by an experienced observer and two inexperienced ones by blinded administration of DRS2. Results -The bivariate correlation between risk classification and risk index calculated as a parametric correlation r of Pearson (Pearson’s Correlation Coefficient), and nonparametric correlation Spearman rho (Rank Correlation Coefficient) highlights a significance of r = 0.777 p = 0.01: ρ = 0.790 p = 0.01. The analysis of the Roc curve shows the levels of sensitivity and specificity with an area under the curve of 0.90 and a p value = 0.001, with a confidence interval (CI) between 0.822 and 0.952. The concordance of the two scales, the screening test and the endoscopic evaluation of swallowing, is equal to 0.93 or 93% (with P-value = 0.0001). The data analysis on the inter-observer reproducibility of the DRS2 score shows the agreement is perfect as the Cohen’s Kappa value is between 0.81 and 1.00. Conclusion - Statistical analysis demonstrated the validity of DRS2, which proved to be a reliable and sensitive tool for detecting the risk of dysphagia in a population of patients suffering from acute stroke. DRS2 assessments are reproducible, also in case of administration by operators without a specific experience, if they undergo a specific training. The tool has also been well accepted by operators for its simplicity and execution rate.