Nonrestorative sleep scale: reliable and valid for the Chinese population

The Effects of Dialysis Modality and Emotional Distress on Fatigue in Patients Undergoing Dialysis

INTRODUCTION

Fatigue is a common but often overlooked symptom in dialysis patients. Factors affecting fatigue in dialysis patients are currently unclear. There are few studies on the effects of mental factors and dialysis modality on fatigue. This study aims to explore the potential relationship between fatigue and insomnia, as well as psychiatric disorders such as anxiety and depression among patients who undergo peritoneal dialysis (PD) or hemodialysis (HD).

METHODS

There were 96 HD patients and 160 PD patients at our hospital who voluntarily participated in the survey. A questionnaire survey was conducted to gather general characteristics of the patients and to evaluate fatigue, sleep quality, anxiety, and depression levels among PD and HD patients.

RESULTS

The overall fatigue score was 53.83 ± 14.22 for the PD group and 57.92 ± 16.35 for the HD group. Notably, the fatigue level was lower in the PD group compared to the HD group (p < 0.05). Univariate analysis indicated that fatigue was associated with occupational status and income in the PD group, as well as educational level and income in the HD group (p < 0.05). Correlation analysis revealed that patients in both groups who were older and had higher scores for insomnia, anxiety, and depression experienced more severe fatigue. Moreover, body mass index was positively correlated with fatigue status in the PD group, while duration of dialysis showed a positive association with fatigue in the HD group. Multivariate regression analysis identified income and depression as major factors influencing fatigue in the PD group, and duration of dialysis, income, and depression in the HD group.

CONCLUSION

Patients who undergo dialysis exhibit high levels of fatigue, with the severity of fatigue being less pronounced in the PD group compared to the HD group. Fatigue in these patients is associated with the duration of dialysis, income level, and presence of depression.

Adaptation and validation of the Chinese version of the Sleep Quality Questionnaire

STUDY OBJECTIVES

Sleep quality is essential to health. The current study aimed to adapt and validate the Sleep Quality Questionnaire (SQQ) into Chinese language.

METHODS

The Chinese version of the SQQ (SQQ-C) was created following the guidelines for cross-cultural adaptation. Compliant with the COSMIN methodology, baseline data (N = 13,325) examined three validity domains and internal consistency, including content validity using the content validity index (CVI) and the cognitive debriefing and focus group (relevance, comprehensiveness and comprehensibility), construct validity using structural validity and cross‑sectional measurement invariance, and criterion validity using concurrent/convergent validity. Follow-up data (N = 3410) gathered within a mean of 168 (167-207) h interval were used to additionally assess longitudinal measurement invariance and test-retest reliability using intraclass correlation coefficient (ICC).

RESULTS

Scale-level CVI/Average was equal to 0.922; Item-level CVIs ranged from 0.889 to 1.000 (excellent), except for item 2 (0.556-fair). A panel of local experts and local participants during cognitive debriefing and focus group stated that it had sufficient relevance and comprehensibility but a slight deficiency in comprehensiveness. Confirmatory factor analysis indicated a stable two-factor structure encompassing Daytime Sleepiness Subscale and Sleep Difficulty Subscale from baseline to follow-up data. The SQQ-C-9 (without item 2) outperformed the SQQ-C-10 (full form). The SQQ-C-9 provided evidence of measurement invariance (strict) across subgroups (cohorts, gender, and age) and across time. The SQQ-C was negatively correlated with the Chinese Nonrestorative Sleep Scale and the Chinese Sleep Condition Indicator. Cronbach's alpha (α), McDonald's Omega (ω), and ICC, respectively, ranged from 0.712 to 0.838, 0.723 to 0.840, and 0.738 to 0.764 for total scale and each subscale.

CONCLUSION

The SQQ-C exhibits adequate psychometric properties and a stable two-factor structure, and should enable valuable assessments of sleep quality in clinical and research settings.

Measurement properties of the simplified Chinese version of Nonrestorative Sleep Scale in adolescents

This study aimed to assess the measurement properties of a simplified Chinese version of the Nonrestorative Sleep Scale (NRSS) among adolescents. We obtained a simplified Chinese NRSS by the standard forward-backward translation procedures and administered it to 486 students who were attending Grade 7-11 in Nanjing, China. Furthermore, Pittsburgh Sleep Quality Index, Athens Insomnia Scale, Centre for Epidemiological Studies Depression Scale, and Toronto Hospital Alertness Test were also self-completed for measuring sleep quality, insomnia, depression and alertness respectively. The sample was randomly split into two halves, with the first half used to explore the scale structure by exploratory factor analysis (EFA), and the second half used to confirm the identified structure by confirmatory factor analysis (CFA). A total of 481 adolescents (49% male) with a mean age of 16 years (range: 13-18) completed this study. In the other half of 250 adolescents, the root mean square error of approximation (RMSEA), standardised root mean square residual, and comparative fit index (CFI) in CFA, which tested the four-factor structure obtained from EFA, were 0.062, 0.051 and 0.975, respectively. Convergent validity was demonstrated from a significant correlation of the simplified Chinese NRSS with sleep quality (r = -0.62), insomnia (r = -0.71), depression (r = -0.60) and alertness (r = 0.54). The internal consistency and test-retest reliability for the global scale were 0.83 and 0.86 respectively. Measurement invariance was established between males and females with the changes of both CFI and RMSEA < 0.01. The simplified Chinese NRSS is valid and reliable for measuring NRS among Chinese adolescents.

Factor Structure of the Children's Sleep Habits Questionnaire in Young Children with and Without Autism

The Children's Sleep Habits Questionnaire (CSHQ) is often used to assess sleep in children with autism spectrum disorder (ASD), but little is known about its factor structure in younger children with ASD. We evaluated alternative factor structures and measurement invariance for CSHQ items in 2- to 4-year-olds with ASD or typical development (TD). Bifactor models indicated subscales' variance was subsumed by a general factor predominantly reflecting sleep initiation and nighttime awakening items. A factor consisting of 7 of these items was measurement invariant across ASD and TD. Thus, comparisons between young children with ASD and TD is appropriate for a measure composed of 7 CSHQ items relating to sleep initiation and awakenings but not for other CSHQ item composites.

Insomnia Disorders: Nosology and Classification Past, Present, and Future

Insomnia is the most common sleep disorder in the adult population. However, the definition of insomnia disorder has varied across major classification systems and changed over time. In the present study, the investigators traced the evolution of insomnia disorder across classification systems, contemplated the empirical basis for its current definitions, and surveyed ongoing research efforts that may clarify insomnia nosology in the future. Three major classification systems for insomnia are the International Classification of Sleep Disorders, the International Classification of Diseases, and DSM. Despite their divergent origins, these classification systems have converged to nearly identical contemporary insomnia definitions. Over time, the emphasis in classification approaches has shifted from symptomatology to etiology to treatment implications. Additionally, the historical multitude of insomnia subtypes has gradually consolidated into a few core diagnoses, reflecting inadequate evidence with which to support subtyping. Current insomnia definitions include frequency and duration criteria to operationalize these diagnoses, while the diagnostic criterion of nonrestorative sleep has been eliminated (with some controversy). In ongoing research efforts, the quest for insomnia biomarkers has not thus far yielded clinically deployable breakthroughs. Data-driven insomnia subtyping suggests a promising new approach in deriving empirically based subtypes; conversely, the transdiagnostic perspective proposes the elimination of categorical distinctions in favor of finding common processes underlying all psychiatric disorders. The continual evolution of insomnia nosology highlights that much remains to be learned about these conditions; all current diagnostic classification systems are best regarded as "works in progress." Nevertheless, refinement and convergence of classification approaches is essential to standardizing insomnia research, diagnosis, and treatment.

International survey for assessing COVID-19's impact on fear and health: study protocol

INTRODUCTION

COVID-19, caused by the SARS-CoV-2, has been one of the most highly contagious and rapidly spreading virus outbreak. The pandemic not only has catastrophic impacts on physical health and economy around the world, but also the psychological well-being of individuals, communities and society. The psychological and social impacts of the COVID-19 pandemic internationally have not been well described. There is a lack of international study assessing health-related impacts of the COVID-19 pandemic, especially on the degree to which individuals are fearful of the pandemic. Therefore, this study aims to (1) assess the health-related impact of the COVID-19 pandemic in community-dwelling individuals around the world; (2) determine the extent various communities are fearful of COVID-19 and (3) identify perceived needs of the population to prepare for potential future pandemics.

METHODS AND ANALYSIS

This global study involves 30 countries. For each country, we target at least 500 subjects aged 18 years or above. The questionnaires will be available online and in local languages. The questionnaires include assessment of the health impacts of COVID-19, perceived importance of future preparation for the pandemic, fear, lifestyles, sociodemographics, COVID-19-related knowledge, e-health literacy, out-of-control scale and the Patient Health Questionnaire-4. Descriptive statistics will be used to describe participants' characteristics, perceptions on the health-related impacts of COVID-19, fear, anxiety and depression, lifestyles, COVID-19 knowledge, e-health literacy and other measures. Univariable and multivariable regression models will be used to assess the associations of covariates on the outcomes.

ETHICS AND DISSEMINATION

The study has been reviewed and approved by the local ethics committees in participating countries, where local ethics approval is needed. The results will be actively disseminated. This study aims to map an international perspective and comparison for future preparation in a pandemic.

Noise sensitivity associated with nonrestorative sleep in Chinese adults: a cross-sectional study

Background

Nonrestorative sleep is a common sleep disorder with a prevalence ranging from 1.4 to 35%, and is associated with various psychological and physical health issues. Noise exposure and noise sensitivity have been proposed to contribute to nonrestorative sleep. This study aimed to examine the relationships among noise, noise sensitivity, nonrestorative sleep, and physiological sleep parameters in Chinese adults.

Methods

A cross-sectional household survey was conducted with randomly selected Chinese adults based on a frame stratified by geographical districts and types of quarters in Hong Kong. We administered a battery of questionnaires, including the Nonrestorative Sleep Scale, the Weinstein Noise Sensitivity Scale, the ENRICHD Social Support Instrument, the Patient Health Questionnaire, and the Perceived Stress Scale to assess nonrestorative sleep, noise sensitivity, social support, somatic symptoms and stress, respectively. Anxiety and depression were evaluated by the Hospital Anxiety and Depression Scale while sociodemographic and lifestyle characteristics were assessed with an investigator-developed sheet. Nocturnal noise level and physiological sleep parameters were measured during nighttime for a week by noise dosimetry and actigraphy, respectively. A structured multiphase linear regression was conducted to estimate associations.

Results

A total of 500 adults (66.4% female) with an average age of 39 years completed this study. Bivariate regressions showed that age, marital status, occupation, family income, season, exercise, cola and soda consumption, social support, somatic symptoms, stress, depression, noise sensitivity, total sleep time, and awakenings were associated with nonrestorative sleep. In the multivariable analysis, family income, season, exercise, social support, somatic symptoms, stress, and depression remained associated with nonrestorative sleep. Specifically, a one-unit increase of noise sensitivity was associated with 0.08 increase in nonrestorative sleep (95% confidence interval [CI]: 0.01, 0.15, p = 0.023). Nocturnal noise was negatively associated with time in bed (b = − 1.65, 95% CI: − 2.77, − 0.52, p = 0.004), total sleep time (b = − 1.61, 95% CI: − 2.59, − 0.62, p = 0.001), and awakenings (b = − 0.16, 95% CI: − 0.30, − 0.03, p = 0.018), but was not associated with nonrestorative sleep.

Conclusions

Nonrestorative sleep was predicted by noise sensitivity in addition to family income, season, exercise, social support, somatic symptoms, stress, and depression.

The association between nonrestorative sleep and health-related quality of life in Chinese adults: a cross-sectional study

PURPOSE

Sleep problems are prevalent among the general population and can cause various health problems, which may lead to decreased quality of life. However, little is known about nonrestorative sleep and its implications. This study aimed to examine the association between nonrestorative sleep and health-related quality of life (HRQL) in Chinese adults.

METHODS

Data were collected through a cross-sectional study of 500 adults in Hong Kong (66.4% female, average age of 39 years). The Short-Form-12 Health Survey version 2 (SF-12v2), Nonrestorative Sleep Scale (NRSS), Pittsburgh Sleep Quality Index, ENRICHD Social Support Instrument, Patient Health Questionnaire, Perceived Stress Scale, and Hospital Anxiety and Depression Scale were administered. Objective sleep parameters were based on participants' sleep condition over 1 week, as measured using an ActiGraph GT9X Link.

RESULTS

Mean standardized scores for the physical component summary (PCS) and mental component summary (MCS) of the SF-12v2 and the NRSS were 50.33 ± 6.50, 49.00 ± 9.03, and 64.77 ± 12.75, respectively. After adjusting for sociodemographic and lifestyle characteristics, sleep quality, objective sleep parameters, social support, somatic symptoms, stress, anxiety, and depression, NRSS scores were associated with PCS (b = 0.12, 95%CI: 0.06 to 0.18, p < 0.001) and MCS (b = 0.08, 95%CI: 0.02 to 0.15, p = 0.013) scores. Furthermore, associations of NRSS score with PCS as well as MCS scores were stronger in women than in men.

CONCLUSION

Nonrestorative sleep is a potentially modifiable risk factor for poor HRQL. Thus, interventions to relieve or decrease nonrestorative sleep could be beneficial for improving HRQL.

Association between Non-Restorative Sleep and Quality of Life in Chinese Adolescents

To examine non-restorative sleep and its impact on quality of life (QOL) in Chinese adolescents, this cross-sectional study included 2827 students aged 12–20 who were selected from 15 secondary schools in Hong Kong, China. Non-restorative sleep was assessed by a single item, rated on a 0–10 scale: “To what extent did you feel refreshed upon awakening over the past month?”. QOL was evaluated by the World Health Organization Quality of Life Measure—Abbreviated Version Hong Kong Chinese Version. Univariable and multivariable linear mixed-effects regressions were conducted to examine the influence of non-restorative sleep (NRS) on QOL. In the present sample, the mean overall QOL was 13.83, and the extent of feeling refreshed upon awakening was 4.75 on average. In multivariable linear mixed-effects regression, one unit feeling less refreshed upon awakening was associated with 0.37 units of poorer overall QOL after adjusting for age, gender, medical conditions, parental education and occupation, weekly hours of aerobic exercises, smoking and drinking habits. Additionally, adolescents with a significantly poorer overall QOL were more likely to be older, have medical problems, have parents with an educational level of primary school or below, have an unemployed father, engage in less weekly aerobic exercise, and be current smokers or former drinkers. Adolescents who experienced non-restorative sleep had a poorer QOL. Future studies are needed to alleviate non-restorative sleep to improve health outcomes in adolescents.

Nonrestorative sleep scale: a reliable and valid short form of the traditional Chinese version

Purpose

Previous research has suggested the essential unidimensionality of the 12-item traditional Chinese version of the Nonrestorative Sleep Scale (NRSS). This study aimed to develop a short form of the traditional Chinese version of the NRSS without compromising its reliability and validity.

Methods

Data were collected from 2 cross-sectional studies with identical target groups of adults residing in Hong Kong. An iterative Wald test was used to assess differential item functioning by gender. Based on the generalized partial credit model, we first obtained a shortened version such that further shortening would result in substantial sacrifice of test information and standard error of measurement. Another shortened version was obtained by the optimal test assembly (OTA). The two shortened versions were compared for test information, Cronbach’s alpha, and convergent validity.

Results

Data from a total of 404 Chinese adults (60.0% female) who had completed the Chinese NRSS were gathered. All items were invariant by gender. A 6-item version was obtained beyond which the test performance substantially deteriorated, and a 9-item version was obtained by OTA. The 9-item version performed better than the 6-item version in test information and convergent validity. It had discrimination and difficulty indices ranging from 0.44 to 2.23 and − 7.58 to 2.13, respectively, and retained 92% of the test information of the original 12-item version.

Conclusion

The 9-item Chinese NRSS is a reliable and valid tool to measure nonrestorative sleep for epidemiological studies.

Electronic supplementary material

The online version of this article (10.1007/s11136-020-02523-4) contains supplementary material, which is available to authorized users.