Contextual factors and perceived self-reported sleepiness: a preliminary report

Abstract 

Objectives: The purpose of the present study was to determine whether contextual factors affect self-reported sleepiness. Specifically, when a reference situation is held constant (e.g. watching television), does the respondent's position, location, or interest in the activity alter sleepiness rating. We also evaluated interactions between an individual's level of sleepiness and the effect of these contextual factors.

Method: This is a prospective survey conducted at a teaching hospital. Samples were drawn from four populations: a general non-patient population (n=53), a geriatric population (n=22), a medical resident population (n=18), and patients referred for sleep evaluation (n=53). We developed and administered a questionnaire that included a list of activities varied according to respondent's position, location, or interest in the activity. This questionnaire, along with the Epworth Sleepiness Scale (ESS), was administered to 146 individuals.

Results: Overall, we found significant differences (P<0.01) in self-reported sleepiness when contextual factors were varied. However, the influence of contextual factors declined as a function of increasing sleepiness (estimated using ESS scores).

Conclusions: The results of this preliminary study indicate that contextual factors can influence self-reported sleepiness rating; however, this influence diminishes as sleepiness increases. Thus, clarifying context may improve test sensitivity in more alert individuals but does not appear to add incremental value to self-reported sleepiness in sleepy patients.

Keywords:  Self-reported sleepiness, Subjective sleepiness, Contextual parameters