Abstract Introduction Sleepiness is a construct of significant clinical and research interest. Current self-report questionnaires have some limitations, such as asking about sleepiness in situations that an individual might not encounter. We designed the Sleepiness, Wakefulness, And Napping Symptoms (SWANS) scale to address this gap, and assessed the comprehensibility and psychometric properties of the scale among a representative sample of adults in the U.S. Methods We conducted expert content review and lexile analysis. We then administered SWANS and other self-reported sleep health measures via YouGov.com (N=2,000; stratified by age, sex assigned at birth, and racial/ethnic identity, representative of the U.S. population). We explored the associations of SWANS items and total scores with legacy measures to establish the construct validity of SWANS. We also conducted receiver operating curve (ROC) analyses to identify thresholds for identifying individuals with and without self-reported sleep disorder symptoms. Results SWANS scores ranged across the entire scale (0 to 36), with an average score of 9.88±6.46. SWANS scores correlated with Ru-SATED 4.0 multidimensional sleep health total scores and alertness scores (|rs|= 0.49 and 0.52, respectively). SWANS scores demonstrated acceptable convergent validity (|rs|= 0.52 to 0.75) with other sleep scales (Epworth Sleepiness Scale, PROMIS Sleep-Related Impairment, Pittsburgh Sleep Quality Index), and significantly differed among those with (n=441, 22%) and without (n=1,558, 78%) sleep disorder symptoms (Cohen’s d=-1.23, 95% CI=6.45 to 7.66), indicating acceptable known-groups validity. ROC analyses indicated that a score of 11 was the optimal threshold for identifying those with/without a sleep disorder (AUC=0.79). Conclusion These findings support the psychometric validity of the SWANS scale as a brief, easy-to-complete survey designed to measure symptoms of sleepiness, wakefulness, and napping. The SWANS may be a viable and helpful tool for assessing the construct of sleepiness in health care and research settings. Future analyses using Item Response Theory will examine the properties of each item to normalize the scale for the general population. Future research is also warranted among clinical populations and on the sensitivity of the SWANS measure to changes in sleepiness following intervention to promote precision medicine approaches. Support (if any) Supported by an investigator-initiated, industry-sponsored research grant from Sleep Number Corporation (PI: Conlon).
Conlon et al. (Fri,) studied this question.