Understanding the effect of rumination on sleep quality: a mediation model of negative affect and bedtime procrastination

Demographic predictors of bedtime procrastination in the Japanese population

Bedtime procrastination (BP) is prevalent and problematic, with no previous study conducted in Japan. This study developed the Japanese version of the Bedtime Procrastination Scale (BPS), assessed its validity, and investigated the relationship between BP, demographic features, and sleep outcomes. Participants were divided into two samples (N = 252 and N = 630). Sample 1 involved a longitudinal study to confirm test-retest reliability of the BPS. Sample 2 involved a cross-sectional study to assess confirmatory factor analysis, criterion-related validity, construct validity, and determine the internal consistency of the BPS. The relationship between BP and demographic features (gender, age, and employment status) and sleep outcomes (Athens Insomnia Scale, sleep hours, sleep onset latency, and sleep efficiency) was investigated using Sample 2. The BPS showed good internal consistency (Cronbach's α coefficients = .90-91), test-retest reliability (ICC = .86), and one factor model was valid; CFI = .95, TLI = .94, RMSEA = .10, and SRMR = .04. The BPS had a moderate positive association with general procrastination, moderate negative associations with self-control, sleep quality, and sleep duration on weekdays, and those who answered "yes" to the item "Do you have trouble with bedtime procrastination?" had higher BPS scores. BPS scores were moderately higher for younger participants (≤ 40 years), slightly higher for females, and non-significantly different between employment statuses. The BPS showed a significant positive correlation with insomnia symptoms, weak positive association with sleep efficiency on weekdays and holidays, and no significant association with sleep onset latencies on holidays and weekdays. This study provides new data on demographic predictors of BP in Japan. No clear effects of gender and employment status were found, but age was a strong predictor of BP, where younger age groups had a higher BP risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-023-00508-7.

Relationship between Problematic Smartphone Use, Sleep Quality and Bedtime Procrastination: A Mediation Analysis

The purpose of this investigation was to study the relationship between sleep quality, problematic smartphone use (PSU) and bedtime procrastination, as well as to assess gender and age differences. A total of 313 participants, aged 18-60 (M = 30 ± 10.1; 53.2% males), completed an online survey between February and May 2023 in Spain. The Pittsburgh Sleep Quality Index, Smartphone Addiction Scale-Short Version and Bedtime Procrastination Scale were used to measure sleep quality, PSU and bedtime procrastination, respectively. Additionally, smartphone use habits were evaluated through self-report questions. Pearson correlations, independent samples t-tests, one-way ANOVA, Bonferroni's post hoc tests and mediation analysis were conducted. Correlation analysis showed positive associations between the three main variables. Independent sample t-tests indicated females were more prone to PSU along with higher overall smartphone use. Post hoc analysis of one-way ANOVA exposed age differences between young adults (18-25 years old), adults (26-44 years old) and middle-aged adults (45-60 years old) in PSU and bedtime procrastination. Finally, mediation analysis revealed that PSU had indirect effects on sleep quality through bedtime procrastination, but no direct effects on sleep quality. Therefore, PSU, and especially bedtime procrastination, should be considered as targets in future campaigns or intervention programs to improve sleep quality among the young Spanish population.

Go to bed! A systematic review and meta-analysis of bedtime procrastination correlates and sleep outcomes

Bedtime procrastination is defined as the volitional delay of going to bed, without any external circumstances causing the delay, and is associated with inadequate sleep. Alleviating bedtime procrastination is an important target for interventions promoting adequate sleep, yet the correlates of bedtime procrastination are poorly understood. This study examined (1) correlates of bedtime procrastination, and (2) strength and direction of the association between bedtime procrastination and sleep outcomes. Six databases (CINAHL, EMBASE, PsychINFO, PubMed, Scopus, Web of Science) were searched from inception to September 2021 against pre-determined eligibility criteria. Forty-three studies were included (GRADE = low). Meta-analysis revealed that bedtime procrastination had a moderate negative association with self-control (z = -0.39; CI: -0.45, -0.29) and a moderate positive association with evening chronotype (z = 0.43; CI: 0.32, 0.48). Furthermore, bedtime procrastination was moderately negatively associated with sleep duration (z = -0.31; CI: -0.37, -0.24), sleep quality (z = -0.35; CI: -0.42, -0.27) and moderately positively associated with daytime fatigue (z = 0.32; CI: 0.25, 0.38). Further high-quality studies are needed to identify causal relationships between bedtime procrastination and correlates, as well as bedtime procrastination and sleep. Future work will guide the development of interventions targeting bedtime procrastination for improved sleep outcomes. STUDY REGISTRATION: PROSPERO registration number CRD42021248891.

Chronotype and poor sleep quality in young adults - a pilot study on the role of rumination

BACKGROUND

Eveningness has been associated with poor sleep quality and depression. However, chronotype has also been shown to be a multidimensional construct, not limited to a merely morningness-eveningness orientation. It has also been proposed that other factors may also mediate the relationship between chronotype and its mental health sequelae. This pilot study explores the role of rumination as a mediator between chronotype and sleep quality, chronotype and depressive symptoms.

METHODS

A sample of 144 participants completed The Morningness-Eveningness-Stability-Scale Improved (MESSi), Pittsburgh Sleep Quality Index (PSQI), Rumination-Reflection Questionnaire (RRQ) and Center for Epidemiologic Studies Depression Scale (CES-D)). The results were tested using Spearman's rank correlation coefficient, multiple linear regression and the Sobel test.

RESULTS

Rumination was linked to poor sleep quality and increased depression. Morning affect and Distinctness (i.e. rigidity, or the subjective amplitude of the circadian rhythm) correlated with rumination. Rumination was a partial mediator of the associations between Morning Affect and sleep quality, Morning Affect and depression.

CONCLUSIONS

Rumination may play a role in the association between chronotype (particularly Morning Affect and Distinction) and sleep quality and depression. The recognition of this association might serve as a basis for clinical psychoeducational and therapeutic programs targeting both adjustment of the circadian rhythm and rumination as a psychopathological sign.

Off-Time Work-Related Smartphone Use and Bedtime Procrastination of Public Employees: A Cross-Cultural Study

While previous studies have examined the negative effects of work-related smartphone use after hours, little is known about whether and how it influences employees’ unhealthy sleep behavior (i.e., bedtime procrastination). Drawing on the ego depletion theory, this study explored the effects of work-related smartphone use after hours on bedtime procrastination. To further uncover potential cross-cultural differences, a sample of 210 public employees from the United States and 205 public employees from China were used. Results via path analysis revealed that off-time work-related smartphone use positively influenced bedtime procrastination via the mediating role of self-control depletion. These findings were consistent between the United States and Chinese sample; however, off-time work-related smartphone use after hours increased the likelihood of self-control depletion more strongly in the United States than in China. The implications of our findings for both theory and practice were discussed.