Development and Preliminary Validation of a Novel Tool to Measure Negative and Positive Affect for Sleep (NAP-AS)

The PANAS is the most widely used measure to detect changes in mood following sleep loss. Although insufficient sleep is associated with enhanced negativity, negative affect items on the PANAS appear unaffected. We examined whether PANAS items were deemed relevant to sleep and subsequently developed a novel tool reflecting changes in negative and positive affect with sleep (NAP-AS).

Four hundred and forty-nine online respondents (18-79y) indicated the extent to which 100 positive and negative word-items (n = 48 new; n = 52 from any PANAS) were useful in describing the experience of insufficient sleep. Using factor analysis, a new questionnaire to reflect changing mood in relation to insufficient sleep was developed and validated under sleep deprivation conditions (n = 24, 18-34y).

Four out of 10 original negative affect (NA) PANAS items (and 0/10 positive affect (PA) items) were deemed irrelevant to sleep by >50% of respondents ("guilt", "afraid", "scared", "ashamed"). To address this, we developed the NAP-AS using factor analysis (from 100 word items) resulting in 14 items reflecting NA and PA (71.4% new items for PA and NA equally; final fit model: RMSEA = 0.048, CFI = 0.98). In a validation study, this tool was sensitive to sleep deprivation (p < .001), such that NA significantly increased (p = .017, d > 0.47), while PA decreased (p < .001, d > 0.75), relative to when well-rested.

Despite the PANAS being a valid tool assessing changes in affect, several items appear irrelevant to the experience of poor sleep. The NAP-AS was developed to specifically capture changes in positive and negative affect following insufficient sleep. The new tool was sensitive to sleep loss, although further validation for clinical populations is recommended.