DSPS-4: a Brief Measure of Perceived Daytime Sleepiness
Sleepiness is a key issue in sleep medicine but its definition remains ambiguous and difficult to address. Some studies have reported that sleepiness should be conceptualized as a multidimensional construct. One of these dimensions is sleepiness propensity accurately assessed by the Epworth Sleepiness Scale. However, in the literature, data on other important sleepiness dimensions, such as sleepiness perception, are lacking. In an attempt to fulfil the literature gaps, this study aims at presenting data regarding the development of a brief self-report instrument to assess daytime sleepiness perception, the Daytime Sleepiness Perception Scale (DSPS-4). A sample of 692 undergraduate Medicine students was initially enrolled. The sample was randomly split in order to perform independent exploratory (EFA) and confirmatory factor analyses (CFA). A one-factor solution was examined. The DSPS-4 showed good indicators of reliability and validity. The CFA confirmed the one-factor structure of the DSPS-4. The unidimensional structure of the scale was invariant for both sexes. Results highlight the usefulness of DSPS-4 to measure and assess sleepiness perception at daytime. The short length of this scale enables its incorporation in routine assessment protocols for example regarding insomnia complaints. However, more studies are now required to check its suitability for other samples, specifically well-defined clinical groups.
KeywordsSubjective daytime sleepiness Sleepiness perception Scale development Validation Sleep
The co-operation of the professors and students is gratefully acknowledged. The authors would like to express their gratitude to the anonymous reviewers for their suggestions and comments. Thanks are also due to Dr. Anabela Soares (PhD) for her contribution in English proofreading.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article does not contain any studies with animals performed by any of the authors.
Informed consent was obtained from all individual participants included in the study.
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