Sleep plays a vital role in cognitive functioning, physical health, and daily performance. Previous research has examined sleep behaviours such as screen usage, sleep timing regularity, and daytime exercise. However, no study has examined a broad range of behaviours collectively and their relation to sleep quality, or the moderating effect of consistency of these behaviours on this relationship.

This study investigated the association between helpful and unhelpful sleep behaviours and self-reported sleep quality, and whether consistency of behaviours moderated these relations. Consistency was categorised into three domains: arousal-related, stimulant-related, and timing-based behaviours. A seven-day sleep diary design was used, where participants retrospectively reported nightly sleep behaviours and sleep quality. 136 participants provided usable data, with 788 diary entries. The use of multilevel linear mixed-effects models accounted for the repeated-measures design.

Results yielded no significant association between helpful or unhelpful behaviours and sleep quality. Additionally, all consistency domains did not significantly moderate the relationship. When observing the variance, 41% of sleep quality variance occurred between individuals, indicating a large influence of stable individual differences in baseline sleep quality across participants.

The findings suggest individual characteristics may have a larger influence on sleep quality than nightly sleep behaviour variation. Future research may better understand the relation between behavioural consistency and sleep quality when employing a longer-term study design that incorporates baseline sleep quality measures and stable individual factors.