Intraindividual Variability of Sleep Opportunity Attitudes, Perceived Norms, Perceived Behavioral Control, and Intentions

Abstract Background Recent research has used the theory of planned behavior (TPB) to predict sleep. However, this research has focused on between-person effects and has failed to capture the intraindividual variability of sleep-related attitudes, subjective norms, perceived behavioral control, and intentions. Purpose The current study sought to characterize the between- and within-day patterns of these constructs. Methods Participants (N = 79) completed a 1 week ecological momentary assessment protocol in which they reported their attitudes, subjective norms, perceived behavioral control, and intentions toward nightly sleep opportunity four times per day. Results Analyses revealed both between- and within-day variability of these constructs, with perceived behavioral control and intentions demonstrating greater variability than attitudes and subjective norms. Mixed linear models revealed that attitudes and subjective norms significantly increased throughout the week, while perceived behavioral control and intentions significantly decreased throughout the day. Conclusions The between- and within-day patterns of the TPB constructs highlight important methodological considerations and provide insight into the potential refinement of sleep promotion efforts. In healthy young adults, thoughts about sleep may change both throughout the week and across a day.