Reliability and external validity of the six scales of 72-item Sleep-Wake Pattern Assessment Questionnaire (SWPAQ)

Abstract

The 72-item Sleep-Wake Pattern Assessment Questionnaire (SWPAQ) provides possibility to self-assess individual variation along as many as 6 factorial dimensions. We examined reliability and external validity of each of its 12-item scales, E, M, W, V, F, and S (evening and morning lateness, anytime and daytime wakeability, anytime and night-time sleepability, respectively). Questionnaire data were collected from residents of Novosibirsk and two smaller Russian cities (N = 755 and 720, respectively). Analysis of these two data-sets suggested good and acceptable internal consistency of each of the scales, respectively. Evidence for external validity of each of the 6 scales was obtained by applying stepwise linear regression analysis to data collected from 160 participants of sleep deprivation experiments who were asked to self-report 6 characteristics of their sleep for a week prior to the experiment. As expected, predictors of scales? scores were a later self-reported time for going to bed (E, W), an earlier/later time for final awakening (W/M), a shorter/longer sleep latency (F, S/E), a shorter/longer total sleep time (W + V/F), a lower/higher sleep satisfaction score (M/W + V), a lower/higher nap frequency (V/F), and a lower self-scored sleepiness after deprivation from sleep for a night (W, V).

Keywords:

• Sleep–wake adaptability
• factor analysis
• validation
• internal consistency
• reliability
• chronotype

Acknowledgment

The authors are indebted to Dr Evgeniy Verevkin for his help in collection of questionnaire and experimental data-sets.