Abstract W P224: SOS Score: an Optimized Score to Screen Acute Stroke Patients for Obstructive Sleep Apnea

Background: Obstructive sleep apnea (OSA) is frequent in acute stroke patients and is associated with increased mortality and poor functional outcome. Polysomnography (PSG) is the gold standard diagnostic method for OSA, but it is impracticable as a routine for all acute stroke patients. We evaluated how OSA screening tools such as the Berlin Questionnaire (BQ) and the Epworth Sleepiness Scale (ESS) would perform when administered to relatives of stroke patients in the acute setting, and compared these individual tools against a combined screening score (SOS score). Methods: Ischemic stroke patients were submitted to a full PSG at the first night after symptoms onset. OSA severity was measured by apnea-hypopnea index (AHI). BQ and ESS were administered to relatives of stroke patients before the PSG. We combined elements of the BQ and ESS to create a new screening tool for OSA named Sleep Obstructive apnea score optimized for Stroke (SOS score). Results: Thirty-nine consecutives ischemic stroke patients were enrolled in our study. The mean age was 62.3 ±12.2 years. Age was significantly different between those with and without OSA (p=0.02). The mean body mass index and neck circumference were 26.7 ± 4.7 and 38.9 ± 4.0cm, respectively. OSA (AHI ≥ 10) was present in 76.9%. The area under the curve for SOS score (AUC:0.812; p=0.005) was superior to BQ (AUC:0.567; p=0.549) and also to ESS (AUC:0.646; p=0.119 vs. AUC:0.686; p=0.048) for severe OSA (IAH ≥ 30). The threshold of SOS ≤ 10 (present in 20.5% of patients) showed high sensitivity (90%) and negative predictive value (96.2%) for OSA; SOS ≥20 (17.9% of patients) showed high specificity (100%) and positive predictive value (92.5%) for severe OSA. Using SOS as a screening approach would decrease by around 40% the demand for PSG during the acute stroke setting. Conclusions: The SOS score when administered to relatives of stroke patients appears to be an appropriate tool to screen acute stroke patients for OSA, while decreasing the need for a formal sleep study during the acute stroke setting. The new derived SOS score is superior to BQ and ESS for identifying patients with OSA and Severe OSA during the acute phase of stroke.