Assessment of Daytime Sleepiness in Clinical Populations

Daytime sleepiness is a prevalent and often disabling symptom encountered across a spectrum of clinical disorders, from central hypersomnolence syndromes to secondary sleepiness in cardiovascular, metabolic and psychiatric conditions. Its evaluation relies on both subjective instruments and objective laboratory tests in order to identify severity, temporal patterns and underlying causes. Self-report scales are widely employed to screen large cohorts and guide treatment decisions, while neurophysiological assessments provide quantification of sleep propensity and architecture. Accurate measurement is crucial for risk stratification, tailoring of interventions and prevention of adverse outcomes such as cognitive decline, impaired quality of life or accidents. Recent advances have highlighted the fluctuating nature of sleepiness, the interplay of lifestyle and mood factors in its onset, and the importance of validating assessment tools across diverse populations.

Research from Nature Portfolio

Longitudinal research has shed new light on the natural history and predictors of excessive daytime sleepiness. In a five-year community study of over 2 000 adults using repeated self-assessments with the Epworth Sleepiness Scale, one third of participants exhibited persistent sleepiness, while a similar proportion developed new or worsening symptoms. Younger age, depressive mood, insomnia and modifiable lifestyle factors such as low caffeine consumption and smoking were identified as independent predictors of incident sleepiness. In contrast, persistent sleepiness clustered with chronic medical comorbidities, suggesting a subgroup requiring intensified clinical management and monitoring.

Assessment of Daytime Sleepiness in Clinical Populations publication trend

The graph below shows the total number of articles in assessment of daytime sleepiness in clinical populations across all publications each year (not limited to Nature Index journals).

Technical terms

Excessive Daytime Sleepiness (EDS): A state of persistent difficulty in maintaining wakefulness or an increased propensity to fall asleep during usual waking hours, impairing normal function.

Epworth Sleepiness Scale (ESS): A simple eight-item questionnaire that quantifies the likelihood of dozing in everyday situations, yielding a score from 0 to 24 to screen for EDS.

Polysomnography: A comprehensive overnight recording of brain waves, eye movements, muscle tone and respiratory parameters used to diagnose sleep disorders.

Multiple Sleep Latency Test (MSLT): An objective measure of daytime sleep propensity involving a series of nap opportunities in a controlled laboratory setting to calculate mean sleep latency.

References

1. Incidence, worsening and risk factors of daytime sleepiness in a population-based 5-year longitudinal study. Scientific Reports (2017).
2. The role of cardiovascular health and vascular events in the relationship between excessive daytime sleepiness and dementia risk. Journal of Sleep Research (2023).
3. Epworth sleepiness scale: A meta-analytic study on the internal consistency. Sleep Medicine (2023).