A three-item instrument for measuring daytime sleepiness: The observation and interview based diurnal sleepiness inventory (ODSI)

Abstract

Study Objectives: We aimed to develop a new three-item assessment tool for daytime sleepiness in older adults, the Observation and interview-based Diurnal Sleepiness Inventory (ODSI) and determine its validity, internal consistency, test-retest reliability, and optimal cutoff score. Methods: A total of 133 elderly subjects including 73 patients with obstructive sleep apnea (OSA) (mean age, 79 y) and 60 controls (mean age, 80 y) were consecutively enrolled and answered all questionnaires. The ODSI questionnaire was validated using the Epworth Sleepiness Scale considered as a gold standard. Reliability, validity, and cut-points were tested. Results: The ODSI has acceptable validity, internal consistency, and test-retest reliability properties. The ODSI has internal consistency and a reliability coefficient (Pearson rho) of 0.70 for its three items, which suggests strong reliability. The estimated sensitivity and specificity were 0.842 with 95% confidence interval [0.624; 0.945] and 0.851 [0.761; 0.911], respectively. The consistency of summated scale scores during test and retest sessions was high (r = 0.970, 95% bootstrap confidence interval [0.898; 0.991]). Receiver operating characteristic analysis suggests that a cut-point of 6 is effective for identifying older adults with excessive levels of daytime sleepiness. Conclusions: The ODSI is a brief, valid, easy-to-administer three-item assessment that can screen for excessive daytime sleepiness among elderly patients with OSA.