Discrepancy between desired time in bed and desired total sleep time in patients with cancer: The DBST index and its relationship with insomnia severity and sleep onset latency

The Pittsburgh Sleep Quality Index (PSQI) Applied to Cancer Patients: Psychometric Properties and Factors Affecting Sleep Quality

OBJECTIVE

Cancer patients frequently report sleep problems. The Pittsburgh Sleep Quality Index (PSQI) is a 19-item instrument for assessing sleep problems. The main objective of this study was to analyze the usefulness of the PSQI in oncological research.

METHODS

A sample of 1,733 cancer patients with mixed diagnoses were included. In addition to the PSQI, the following questionnaires were adopted: the Insomnia Severity Index (ISI), the Jenkins Sleep Scale (JSS) and the sleep scale of the EORTC QLQ-SURV100.

RESULTS

The internal consistency of the PSQI was α = 0.79. Of the PSQI subscales, the subjective sleep quality correlated most strongly with the other sleep instruments (r between 0.68 and 0.77). In total, 69.2% of the sample were poor sleepers; the effect size of the difference between the PSQI total scores of the patients and a general population sample was d = 0.83. Female patients experienced more sleep problems than male patients (d = -0.49), and younger patients (<60 years) reported more sleep problems than older patients (≥60 years) (d = 0.21).

CONCLUSIONS

The PSQI can be recommended for use in clinical practice since its sub-dimensions provide detailed information on the sleep situation of cancer patients.

Preoccupation with sleep and dysfunctional beliefs about sleep mediate the influence of psychological inflexibility on insomnia in the older adult population

INTRODUCTION

This study aimed to explore whether the Discrepancy between the desired time in Bed and the desired total Sleep Time (DBST) index influences insomnia severity in the older adult population and examined the potential role of psychological inflexibility in this association.

METHODS

An online survey study was conducted for older individuals aged ≥ 65 via a survey company between January and February 2023. A total of 300 responses and data without personally identifiable information were delivered to the researchers. The survey questionnaires include the DBST, Glasgow Sleep Effort Scale (GSES), Insomnia Severity Index (ISI), Dysfunctional Beliefs about Sleep-2 items (DBS-2), and Acceptance and Action Questionnaire-II (AAQ-II).

RESULTS

The analysis included 295 older adult participants. The DBST index was significantly correlated with all questionnaires. Linear regression revealed the DBST index was predicted only by the ISI (β = 0.26, p = 0.003). Mediation analysis showed that the GSES (Z = 2.92, p = 0.003) and DBS-2 (Z = 2.17, p = 0.030) mediated the effect of the DBST index on the ISI, while the AAQ-II did not. Path analysis showed that the DBST could be directly predicted by the ISI (Z = 2.94, p = 0.003), GSES (Z = 2.75, p = 0.006), and DBS2 (Z = 2.71, p = 0.007) but not by the AAQ-II itself. However, the AAQ-II exerted a significant indirect effect on the ISI through the DBS-2 (Z = 2.21, p = 0.027) and GSES (z = 2.24, p = 0.025).

CONCLUSIONS

Our study showed that preoccupation and dysfunctional beliefs about sleep may mediate the relationship between the DBST index and insomnia severity in the older adult population. We opine that psychological inflexibility might play a significant role in insomnia severity via preoccupation with and dysfunctional beliefs about sleep.

Discrepancy Between Desired Time in Bed and Desired Total Sleep Time, Insomnia, Depression, and Dysfunctional Beliefs About Sleep Among a Clinical Sample of Patients With Insomnia

OBJECTIVE

This study investigated whether the discrepancy between desired time in bed and desired total sleep time (DBST) index could be a meaningful indicator for assessing insomnia severity in a clinical sample of patients with insomnia. Furthermore, we sought to identify the mediators of the association between DBST and insomnia severity in individuals with insomnia.

METHODS

We collected the medical records of 127 patients with insomnia. Each participant's DBST index was calculated using sleep indices, including time and duration variables. Psychological symptoms were investigated using the Insomnia Severity Index (ISI), Patients Health Questionnaire-9 items (PHQ-9), Generalized Anxiety Disorder-7, Dysfunctional Beliefs and Attitudes about Sleep-16 items (DBAS-16), and Epworth Sleepiness Scale.

RESULTS

The DBST index was significantly correlated with the ISI (r=0.20, p<0.05), desired total sleep time (r=-0.52, p<0.001), and desired time in bed (r=0.32, p<0.01). Linear regression analysis revealed that insomnia severity was associated with age (β=-0.18, p=0.018), DBST (β=0.23, p=0.003), PHQ-9 (β=0.23, p=0.031), and DBAS-16 (β=0.42, p<0.001). The DBST directly influenced insomnia severity, although indirect effects of mediators were not significant.

CONCLUSION

The DBST index directly influenced insomnia severity regardless of the mediating effects of psychological factors among a clinical sample of patients with insomnia. This finding implies that the DBST index can be a simple measure of insomnia severity, even among patients with insomnia.

Efficacy and safety of digital therapeutic application of Sleep Index-Based Treatment for Insomnia (dSIBT-I): a pilot study

The aim of this study was to evaluate the safety and efficacy of digital therapeutic application of Sleep Index-Based Treatment for Insomnia (dSIBT-I) and compare them with those of digital application of Cognitive Behavioural Therapy for Insomnia (dCBT-I). This randomised prospective pilot study was conducted at the Asan Medical Center. A total of 50 patients with insomnia were recruited between December 2022 and January 2023 and randomly allocated to the dSIBT-I or dCBT-I group. The study was carried out for one month. The primary outcome was the significant reduction in Insomnia Severity Index score at Week 4 compared to baseline, while the secondary outcome was proportion of participants whose Insomnia Severity Index scores were reduced to <15 at Week 4. We performed linear mixed model and generalised estimating equation analyses. Both dSIBT-I and dCBT-I groups showed significant improvements in Insomnia Severity Index scores at Week 4. There was no significant difference between two groups in terms of Insomnia Severity Index scores at Week 4 (group × time effect, F = 1.07, p = 0.382) and proportion of participants whose Insomnia Severity Index scores were reduced to <15 at Week 4 (group × time effects, F = 1.80, p = 0.615). However, at Week 2, the dSIBT-I group showed better results than the dCBT-I group in terms of both Insomnia Severity Index scores (p = 0.044) and proportion of participants whose Insomnia Severity Index scores were reduced to <15 (82.6% vs. 48.0%, p = 0.017). No treatment-emergent adverse events were reported in either group. The dSIBT-I is a safe and effective therapy for insomnia, with rapid treatment effects.

Changes in Insomnia Severity are Associated With the Changes in Discrepancy Between Desired Time in Bed and Desired Total Sleep Time Among the General Population

OBJECTIVE

The discrepancy between desired time in bed and desired total sleep time (DBST index) is correlated with the severity of insomnia among the general population. This study aimed to explore whether the change in DBST index is associated with changes in insomnia severity.

METHODS

The study was conducted as a single source tracking online survey among the general population. The first survey (T1) was completed by all 399 participants, and the second survey (T2) was completed by 233 participants 5-6 weeks after the T1 survey with a simple instruction of reducing the DBST index. Participants' age, sex, marital status, past psychiatric history, and sleep patterns were collected. In addition to the DBST index, the Glasgow Sleep Effort Scale (GSES), Dysfunctional Beliefs about Sleep-2 items (DBS-2), and Insomnia Severity Index (ISI) were rated.

RESULTS

The change in the ISI (T1-T2) was significantly correlated with the changes in the GSES (r=0.24, p<0.001), DBS-2 (r=0.22, p<0.001), and DBST index (r=0.15, p=0.020). The change in insomnia severity was expected with change in the GSES (β=0.23, p<0.001), DBS-2 (β=0.20, p=0.002), and DBST index (β=0.13, p=0.037). Mediation analysis showed that change in DBST index directly influenced change in insomnia severity and change in GSES or DBS-2 did not mediate the relationship.

CONCLUSION

Changing the DBST index can be a simple way to reduce insomnia severity among the general population.