Rethinking the assessment of sleepiness

Sleepiness should be reinvestigated through the lens of clinical neurophysiology: A mixed expertal and big-data Natural Language Processing approach

Historically, the field of sleep medicine has revolved around electrophysiological tools. However, the use of these tools as a neurophysiological method of investigation seems to be underrepresented today, from both international recommendations and sleep centers, in contrast to behavioral and psychometric tools. The aim of this article is to combine a data-driven approach and neurophysiological and sleep medicine expertise to confirm or refute the hypothesis that neurophysiology has declined in favor of behavioral or self-reported dimensions in sleep medicine for the investigation of sleepiness, despite the use of electrophysiological tools. Using Natural Language Processing methods, we analyzed the abstracts of the 18,370 articles indexed by PubMed containing the terms 'sleepiness' or 'sleepy' in the title, abstract, or keywords. For this purpose, we examined these abstracts using two methods: a lexical network, enabling the identification of concepts (neurophysiological or clinical) related to sleepiness in these articles and their interconnections; furthermore, we analyzed the temporal evolution of these concepts to extract historical trends. These results confirm the hypothesis that neurophysiology has declined in favor of behavioral or self-reported dimensions in sleep medicine for the investigation of sleepiness. In order to bring sleepiness measurements closer to brain functioning and to reintroduce neurophysiology into sleep medicine, we discuss two strategies: the first is reanalyzing electrophysiological signals collected during the standard sleep electrophysiological test; the second takes advantage of the current trend towards dimensional models of sleepiness to situate clinical neurophysiology at the heart of the redefinition of sleepiness.

Epworth sleepiness scale: A meta-analytic study on the internal consistency

OBJECTIVE/BACKGROUND

The Epworth Sleepiness Scale (ESS) is one of the most used self-reported instruments to assess sleepiness. Thus, several adaptations into different Languages have been performed worldwide over the years. The scale has produced disparate psychometric properties when applied in different settings. In the current study, our aim was to perform a Reliability Generalization meta-analysis of the Cronbach᾽s alphas of all published studies on ESS, specifically with a psychometric focus.

PATIENTS/METHODS

Three reference databases (Scopus, PubMed and Web of Science) were searched since 1991 to October 2022 and all the records on psychometric or validation studies that reported Cronbach's alphas, from clinical and nonclinical groups, were included. In total, data from 46 publications (63 estimates) were extracted, comprising 92,503 participants.

RESULTS

Using a Random-Effects Model, the cumulative Cronbach's alpha for the 63 estimates was about 0.82 (CI: 0.798, 0.832) which can be considered as a good measure. However, and as expected, it was observed a high level of heterogeneity (I2 = 98.96%). Moderation analyses considering setting, date, continent, risk of bias, sex, age and language were performed in order to account for the heterogeneity. Even so, only the variables study setting and continent were significant, and had little importance in explaining the heterogeneity.

CONCLUSIONS

The ESS is a reliable tool to measure sleepiness; however, further studies are needed to investigate what variables might explain the observed variability. Moreover, it will be important to include empirical studies beyond psychometric ones.

A high propensity for excessive daytime sleepiness independent of lifestyle is associated with cognitive performance in community-dwelling older adults

Objective

The relationship between excessive daytime sleepiness (EDS) and cognitive performance of older adults remains unclear, especially when a healthy lifestyle is considered. The study aimed to explore the association between EDS in passive and active situations and general cognitive function among community-dwelling older adults.

Methods

Two hundred and seventy-one older adults aged 60 and above were recruited from the community cohort in Shangrao. All study participants were free of depression and dementia. The Chinese version of the Epworth Sleepiness Scale (CESS) was used to evaluate EDS. Using the item scores of CESS, the presence of EDS among all study participants were grouped as non-EDS, passive situation-related EDS (PSR-EDS), active situation-related EDS (ASR-EDS), and high sleep propensity (HSP). The Hong Kong Brief Cognitive Test (HKBC) was used to assess cognitive function. Chinese healthy lifestyle metrics were scored based on AHA Life Simple-7. The multivariate logistic regression model was used to estimate the association between the presence of EDS and cognitive function.

Results

The PSR-EDS (n = 29, 20.8 ± 5.3) and the HSP groups (n = 21, 19.8 ± 4.8) scored lower with HKBC than in the non-EDS group (n = 213, 23.2 ± 4.9). The subdomain performance of language in the HSP group was poorer than in the non-EDS group (ps < 0.05). Relative to non-EDS, HSP (OR = 3.848, 95% CI = 1.398-10.591) was associated with an increased risk of poor cognitive performance after adjusting age, sex, education, and healthy lifestyle metrics.

Conclusion

High propensity for excessive daytime sleepiness, irrespective of lifestyle, is associated with poorer cognitive performance among community-dwelling older adults. The findings may provide empirical evidence to support sleepiness intervention for reducing the risk of cognitive decline.

Revisiting the Epworth sleepiness scale : Is excessive daytime sleepiness still a valid screening tool for obstructive sleep apnea in a population at risk?

OBJECTIVE

Obstructive sleep apnea (OSA) is a common medical problem with numerous comorbidities and high costs. Since the introduction of the Epworth sleepiness scale (ESS), excessive daytime sleepiness (EDS) has been considered the most common and prominent symptom of OSA. Aim of this study was to re-evaluate the ESS for detection of OSA in a population at risk compared to the gold standard overnight polysomnography (PSG).

METHODS

A total of 266 patients (mean age 57.9 ± 11.6 years; 189 men and 77 women), referred to our sleep laboratory for probable OSA, were given ESS followed by an overnight PSG. The ESS values were compared to PSG apnea hypopnea index (AHI) with sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy (DA) calculated for ESS. The positive cut-off value for ESS was ≥ 10 and for AHI ≥ 5.

RESULTS

Only 92 (34.6%) subjects had a positive ESS. An OSA was diagnosed by PSG in 213 (80.1%) subjects: 46 having mild, 37 moderate and 130 severe apnea. Most subjects with positive ESS (88.0%) were found to have OSA but most subjects with a negative ESS (75.9%) were also positive for OSA (42% with AHI ≥ 30). The area under the receiver operating characteristic (ROC) curve for ESS was 0.60 (95% confidence interval, CI 0.54-0.66; p = 0.020) with SE 38.0%, SP 79.3%, PPV 88.0%, NPV 24.1% and DA 46.2%.

CONCLUSION

It was found that excessive daytime sleepiness, measured by ESS, is not a valuable screening tool for OSA, especially when the test is negative. Other screening tests that involve additional parameters, beside daytime sleepiness alone, should be considered.

Sleepiness in adults: An umbrella review of a complex construct

Sleepiness involves many dimensions that require investigation. Since sleepiness is often defined operationally, we exhaustively inventoried all the assessment tools designed to measure it in an umbrella review, without any preconceptions, i.e. a review of reviews. We included all reviews and systematic reviews related to sleepiness assessment tools published up to March 2021. Three investigators independently assessed the eligibility of studies for inclusion and identified 36 relevant reviews. In total, 99 tools were identified and classified into 8 categories. We classified them depending on their category, their publication year and the number of mentions in the 36 included reviews. The 6 most frequently cited were the Epworth sleepiness scale, the multiple sleep latency test, the maintenance of wakefulness test, the Stanford sleepiness scale, the Karolinska sleepiness scale, and the psychomotor vigilance task. Despite the limitation that we may have missed some recently developed tools, this historical perspective on sleepiness measurement is a first step toward a better delineation of the different dimensions underlying the constructs of sleepiness, and will serve as a basis for further discussion in the clinical and research sleep community.

Sleepy, tired, drowsy, and fatigue have different meanings for a university student sample

STUDY OBJECTIVES

This pilot study aimed to investigate differences in the semantic meanings that individuals attribute to the words "sleepy," "fatigued," "tired," and "drowsy."

METHODS

Ninety-six undergraduate students ranked the target words on three independent dimensions (Evaluative, Potency, and Activity) to assess their meaning using the Semantic Differential Technique. Participants also completed online questionnaires to assess their sleep difficulties and current states of sleepiness and fatigue.

RESULTS

There were significant differences between all four words in connotative meaning on the Evaluative dimension, p < .05 for all post-hoc comparisons, with differences largest between "sleepy" and "fatigued." "Drowsy" was significantly closer in meaning to "sleepy" than to "fatigued," p = .04, and "tired" was not significantly closer in meaning to "sleepy" or "fatigued," p = .13. No significant association was found between insomnia severity index scores and "sleepy" ratings, r_(s) = 0.08, p = .42, but a small effect was found with "fatigued" ratings, r_(s) = 0.24, p = .02.

CONCLUSIONS

These preliminary findings indicate that individuals consider these words as distinct concepts, relatively unaffected by the current severity of their insomnia symptoms. This adds to the argument for not using these words interchangeably, which we encourage sleep medicine researchers and clinicians to consider when employing these words in research and clinical practice.

Sleep patterns in patients treated for non-secreting intra- and parasellar tumors: A self-report case-control study

PURPOSE

In this study we evaluate sleep patterns of patients treated for non-secreting intra- and parasellar tumors and age- and sex-matched healthy controls.

METHODS

We conducted a self-report cross-sectional case-control study with 104 patients treated for non-secreting intra- and parasellar tumors and 1800 healthy controls in an 1:8 matching. All subjects answered the Munich ChronoType Questionnaire, whereas patients were provided the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, the Short-Form 36 Health survey, the Beck Depression Inventory and the State-Trait Anxiety Inventory additionally.

RESULTS

Patients treated for non-secreting intra- and parasellar tumors go to bed earlier, fall asleep earlier, need less time to prepare to sleep but also to get up. Additionally, they lie and sleep longer. The subgroup analysis showed that patients with secondary adrenal insufficiency compared to controls experienced shorter daily light exposure and longer sleep latency. Higher hydrocortisone dose (>20mg) was associated with worse score in global, physical and mental health, shorter time to prepare to sleep, earlier sleep onset and longer sleep duration.

CONCLUSION

Our study shows that patients treated for non-secreting intra- and parasellar tumors, even if successfully treated, experience altered sleep patterns compared to controls. We suggest that managing clinicians should enlighten these possible sleep alterations to their patients and use specific questionnaires to document sleep disturbances. Additionally, when treating patients surgically, especially by transcranial approach, damaging the suprachiasmatic nucleus should be avoided. Furthermore, circadian hydrocortisone replacement therapy ideally with dual-release hydrocortisone - if possible, in a dose not more than 20mg daily - that resembles physiological cortisol levels more closely may be beneficial and could improve sleep patterns and sleep-related quality of life.

Evaluation Parameter of Excessive Daytime Sleepiness for Obstructive Sleep Apnea Patients

Background and Objective Obstructive sleep apnea (OSA) is a sleep-related breathing disorder caused by repetitive obstruction of the upper airway. Repetitive obstruction of the upper airway causes impaired gaseous exchange, resulting hypoxia, hypercapnia, and frequent arousals of sleep architecture. Polysomnography (PSG) is a gold standard for diagnosing OSA. Excessive daytime sleepiness (EDS) is a common accompanying daytime symptoms in OSA patients. Since EDS can cause unexpected events such as traffic accident or poor performance in workplace, it is regarded as a significant public health problem. Therefore, accurate assessment and prediction of this symptom is important. The Epworth Sleepiness Scale (ESS) and multiple sleep latency test are most commonly used to evaluate EDS, but their efficacies are controversial. The purpose of this study is to find the parameter to evaluate and predict the EDS for OSA patients.Methods We retrospectively reviewed the medical records of 88 OSA patients. Patients were divided into two groups according to the presence of EDS. We analyzed the clinical records, questionnaire scores, and PSG data to find the difference between two groups.Results ESS was 10.64 ± 4.28 in EDS patients and 8.63 ± 4.86 in non-EDS patients. ESS showed a statistically significant difference between two groups (p = 0.044). Also, the percentage of 1st stage non-REM sleep in total sleep time (N1%) was 25.09 ± 15.24 in EDS patients and 18.97 ± 10.30 in non-EDS patients and showed a statistically significant difference between groups (p = 0.033). Patients’ weight was 81.59 ± 20.52 in EDS patients and 74.14 ± 12.63 in non-EDS patients and showed a statistically significant difference between groups (p = 0.046).Conclusions ESS, N1% and patients’ weight were significant parameter which is related with the presence of EDS for OSA patients. These parameters will be useful in evaluating the presence of EDS for OSA patients. Also, in patients diagnosed with sleep disorder with high N1%, EDS must be accurately evaluated as well.

Measurement Methods of Fatigue, Sleepiness, and Sleep Behaviour Aboard Ships: A Systematic Review

Since seafarers are known to be exposed to numerous job-related stress factors that can cause fatigue, sleepiness, and disturbed sleep behaviour, the aim of this review was to provide an overview of the subjective and objective measurement methods of these strains. Using a systematic review, 166 studies were identified within the period of January 2010 to December 2020 using the PubMed database. Of the 21 studies selected, 13 used both subjective and objective measurement methods. Six studies used only subjective and two studies only objective methods. For subjective assessment, 12 different questionnaires could be identified as well as activity and sleeping logs. Actigraphy and reaction time tests (RTT) were the most common objective methods. In single cases, electrooculography (EOG), pupillometry and ambulatory polysomnography (PSG) were used. Measurement-related limitations due to vessel-related impacts were less often reported than expected. No restrictions of daily routines on board were described, and only single-measurement disturbances due to ship movements were mentioned. The present literature review reveals that there are various routines to measure fatigue, sleepiness, and sleep behaviour on board. A combination of subjective and objective methods often appears to be beneficial. The frequent use of actigraphy and RTT on board suggests good feasibility and reliable measurements with these methods. The use of ambulatory PSG in maritime-like contexts suggests that this method would also be feasible on board.

Prevalence and factors associated with excessive and severe daytime sleepiness among healthcare university students in the Brazilian Midwest

The present study aimed to determine the prevalence of, and factors associated with excessive and severe daytime sleepiness in healthcare university students. A cross-sectional university-based study was conducted with 1,779 students from a university located in the Brazilian Midwest State of Goiás, Brazil, in 2018. Daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS) and classified as excessive daytime sleepiness (EDS; cut-off ESS score ≥10) and severe EDS (S-EDS; cut-off ESS score ≥16). Associated factors included sociodemographic, behavioural, academic, nutritional status, and sleep-related and perceived health characteristics. Poisson regression was used for the data analysis. The mean (SD) age of the sample was 22.5 (3.84) years. The prevalence of EDS was 54.4% (95% confidence interval [CI] 51.9-56.1) and S-EDS was 10.0% (95% CI 9.2-11.7). After adjustment, a higher probability of occurrence of EDS was found among women (prevalence ratio [PR] 1.37, 95% CI 1.24-1.53), younger students (PR 1.23, 95% CI 1.07-1.42), those who were studying medicine (PR 1.14, 95% CI 1.02-1.28), with poor sleep quality (PR 1.29, 95% CI 1.17-1.43), and among those who reported constant loss of sleep due to internet use (PR 1.14, 95% CI 1.02-1.27). After adjustment, the highest probability of occurrence of S-EDS was found among women (PR 1.72, 95% CI 1.22-2.43), among those with poor sleep quality (PR 2.17, 95% CI 1.54-3.08), and medical students (PR 1.39, 95% CI 1.01-1.90). In conclusion, there was a high prevalence of daytime sleepiness among healthcare university students, especially among medical students and women.

Distinguishing the Diagnosis and Management of Sleep Disturbance and Sleep Disorders in Multiple Sclerosis

Sleep is a critical issue for quality of life, cognition, and safety among patients with MS. Sleep disturbances from poor sleep hygiene, and multiple sclerosis symptomology, sleep disorders are prevalent; yet evaluation of sleep and screening of sleep disorders are inconsistent. This article presents commonly observed sleep disturbances and disorders, appropriate screening and diagnostic considerations, and management options. Nurses providing care for patients with MS must recognize sleep as an important component in care planning. A comprehensive sleep history and appropriate screening instruments should be incorporated into initial and ongoing assessments, with referral to sleep medicine providers as indicated.

Relationship between sleep disorders, HIV status and cardiovascular risk: cross-sectional study of long-haul truck drivers from Southern Africa

OBJECTIVES

Long-haul truck drivers (TDs) may have lifestyles that promote cardiovascular disease (CVD), including diet, sleep and activity issues. Most studies conducted among truckers investigated the relationship between poor sleep and cardiometabolic health, but none assessed whether suspected obstructive sleep apnoea (OSA) and shortened sleep were associated with markers of cardiometabolic risk. We determined whether sleep disorders and circadian misalignment were associated with chronic inflammation and CVD risk in TDs from Southern Africa.

METHODS

Participants were recruited at roadside wellness centres in Gauteng and Free State Provinces, South Africa. OSA risk was assessed using the Berlin Questionnaire, while sleep duration and sleep quality were assessed using items from the Pittsburgh Sleep Quality Index. Clinical information, neck circumference (NC), metabolic profile, elevated BP, HIV status and C-reactive protein (CRP) were collected. CVD risk was assessed using the Framingham Risk Score (FRS).

RESULTS

Out of 575 participants aged on average 37.7 years, 17.2% were at OSA risk, 72.0% had elevated BP, 9.4% had HIV and 28.0% were obese. Mean sleep duration was 7.4±1.8 hours, and 49.6% reported working night shift at least once a week. Shortened sleep, OSA risk, age, body mass index, NC and years as full-time TD were associated with greater FRS independently of HIV status and night shift. Working night shift was associated with higher CRP levels in HIV+ compared with HIV- participants.

CONCLUSIONS

Circadian misalignment in HIV, and OSA and short sleep duration in all truckers were associated with increased CVD risk. Truckers should be given careful attention in terms of health management and sleep education.

Working nights and lower leisure-time physical activity associate with chronic pain in Southern African long-distance truck drivers: A cross-sectional study

Background

In South Africa, the trucking industry employs over 70,000 people and the prevalence of chronic pain in this occupational group was reported at 10%. We investigated factors associated with chronic pain in truck drivers including mental health, physical activity, and sleep, as no study has done so.

Methods

Southern African male, long-distance truck drivers were recruited at truck stops in Gauteng and Free State Provinces, South Africa (n = 614). Chronic pain was defined as pain present for at least the last three months. Depressive symptoms were assessed with the Patient Health Questionnaire-9, post-traumatic stress disorder with the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5), exposure to traumatic events with the Life Events Checklist-5 (LEC-5) and daytime sleepiness with the Epworth Sleepiness Scale. Sleep quality was measured on a four-point Likert scale. Leisure-time physical activity was measured using the Godin-Shephard leisure-time physical activity questionnaire. Associations between these factors, demographic factors and chronic pain were investigated.

Results

Multivariate analysis showed that working ≥ 2 nights/week (OR = 2.68, 95% CI = 1.55–4.68) was associated with chronic pain and physical activity was protective (OR = 0.97, 95% CI 0.95–0.98). In an exploratory analysis, greater depressive symptoms (p = 0.004), daytime sleepiness (p = 0.01) and worse sleep quality (p = 0.001) was associated with working ≥ 2 nights/week. Lower leisure-time physical activity was associated with worse sleep quality (p = 0.006), but not daytime sleepiness or depressive symptoms (p>0.05).

Conclusions

There is a clear relationship between working nights and activity levels, and chronic pain, sleep quality, and depression in truck drivers.

Health-related quality of life in patients with non-functioning pituitary adenoma: a special focus on hydrocortisone replacement dose

PURPOSE

Patients with non-functioning pituitary adenomas (NFPA) suffer from pronounced impairments in physical and mental measures that result in an impairment of health-related quality of life (HRQOL). The role of secondary adrenal insufficiency (SAI) and especially the one of the hydrocortisone (HC) replacement dose on the HRQOL seems to be conflicting. The primary aim of this study is to assess the HRQOL in patients with NFPA in terms of presence of SAI and in patients without SAI and the secondary to explore the impact of treatment parameters such as daily HC dose.

DESIGN/METHODS

In a cross-sectional study we evaluated parameters of HRQOL in 95 patients with NFPA of the Endocrine Outpatient Unit of the Max Planck Institute of Psychiatry in Munich using standardized questionnaires like Short Form (SF-36), Beck's Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI) and a self-constructed questionnaire about medical history.

RESULTS

We could not find any significant difference between patients with and without SAI in the standardized questionnaires in terms of HRQOL. We could show that higher doses of HC were negatively correlated with HRQOL measured by SF-36 global health score regardless of using BDI or STAI in the block (β =  - 0.397; p = 0.021, β =  - 0.390; p = 0.016, respectively).

CONCLUSIONS

NFPA patients with SAI do not have a worse HRQOL than patients with NFPA and intact corticotropic axis. We could show that higher doses of HC are associated with an impaired HRQOL measured by SF-36 global and physical health score, whereas mental health score is not significantly influenced by the HC dose.

Topical nasal treatment efficacy on adult obstructive sleep apnea severity: a systematic review and meta-analysis

BACKGROUND

Nasal obstruction is a common complaint in patients with sleep-disordered breathing and obstructive sleep apnea (OSA). Although topical nasal treatments (TNTs) have been shown to reduce nasal resistance and improve nasal obstruction, there is conflicting evidence regarding the role of TNTs in adult OSA. In this systematic review and meta-analysis we aim to evaluate the role of TNTs in adults with OSA. Data sources used included PubMed, Ovid MEDLINE, and Cochrane Central, from January 2001 to July 2019.

METHODS

Inclusion criteria were English-language studies containing original data on TNTs in adults (≥18 years) with OSA (apnea-hypopnea index [AHI] ≥5). Exclusion criteria were case reports, studies without outcome measures, and concurrent non-TNT treatment for OSA. Two investigators independently reviewed all articles and performed quality assessment using validated tools. Meta-analysis and quality assessment were performed.

RESULTS

Of the 2180 abstracts identified, 8 studies met inclusion criteria. TNTs included decongestants (4 of 8 studies), corticosteroids (3 of 8), and antihistamines (1 of 8). Outcome measures included AHI (8 of 8), respiratory distress index (RDI; 1 of 8), oxygen-desaturation index (ODI; 3 of 8), minimum SaO2 (MinSaO₂ ; 4 of 8), nasal resistance (4 of 8), endoscopic sinus surgery (4 of 8 studies) and standardized rhinoconjunctivitis quality of life questionnaire scores (1 of 8 studies). Qualitatively, all studies showed trends toward improving objective and subjective measures of OSA, although the significance of these improvements varied across studies. A meta-analysis was performed in 5 studies, but TNTs did not reveal a significant change in AHI (p > 0.05).

CONCLUSION

TNTs may improve minimum oxygen saturation, ODI, RDI, and subjective/quality-of-life measures. Allergic patients may have more improvement in OSA measures compared with nonallergic patients. Future studies are indicated to accurately determine the efficacy of TNTs.

Poor Subjective Sleep Quality Is Associated with Poor Occupational Outcomes in Elite Soldiers

We aimed to assess the relationship between subjective sleep quality and occupationally-relevant outcomes in military personnel. Participants were from an elite unit of US Army soldiers who worked extended (~30 h) shifts (with minimal recovery time between shifts) during 3-week work sessions. Questionnaires assessing subjective sleep quality during the month prior (Pittsburgh Sleep Quality Index [PSQI]) were administered at the beginning of the session. Occupational outcomes (emotional exhaustion, functional impairment, role overload, daytime sleepiness) were assessed on the final day of the session. Regression analyses were conducted to link sleep quality and occupational outcomes. The study sample participants had relatively poor sleep prior to the exercise (PSQI Global score average = 6.3 ± 3.1). Higher PSQI Global Scores prior to the work session longitudinally predicted daytime sleepiness (f2: 0.56) after the work session. PSQI component 7, which queries daytime dysfunction attributed to poor sleep quality, longitudinally predicted emotional exhaustion, functional impairment, and role overload (f2 range: 0.19-0.70). In conclusion, poor sleep quality-in aggregation with occupationally-mandated sleep loss-is predictive of poorer subsequent occupational outcomes. Future work should aim to increase sleep opportunities prior to occupationally-mandated sleep loss in order to build resilience when sleep loss is unavoidable.

Validation of the Arabic Version of the Epworth Sleepiness Scale among the Yemeni Medical Students

The study was conducted with the aim to assess the psychometric measures of an adapted Arabic version of the Epworth Sleepiness Scale (ESS) among medical students at Sana'a University, Yemen. The cross-sectional study targeted 360 students (males: 176; females: 184) from the preclinical 3^rd year (N: 197) and the final clinical year (N: 163). Participants self-filled an Arabic and slightly modified version of the 8-item Epworth Sleepiness Scale. Exploratory Principal Component Analysis (PCA) and Confirmatory Factor Analyses (CFA) were conducted on two equal subsets of the sample (N: 180 each). The PCA yielded a two-dimension model subsequently confirmed by factor analysis. The first dimension was grouped on three items while the second dimension had five items reflecting the respondents' propensity to sleep during “interactive situations” and “sitting and lying,” respectively. The model had an acceptable goodness of fit measures for the overall ESS (CMINDF = 2.362, CFI = 0.91, IFI = 0.92) and acceptable reliability indicators (factor 1 α = 0.65, factor 2 α = 0.62). However, due to weak variance explanation (0.07) of item 6 (sitting and talking) in factor 1, analysis was repeated excluding this item. The 7-item model was also two-dimensional, valid, and reliable. The reliability indicators were acceptable with α = 0.65 for factor 1 (4 items of interactive situations) and 0.62 for factor 2 (3 items of sitting) and overall α = 0.68. Overall, the ESS is a useful tool. Factor analysis produced a two-factor model of 7 items with good validity and reasonable reliability that can be used in diagnosing daytime sleepiness among young Yemeni adults.

Feasibility of smart wearables for driver drowsiness detection and its potential among different age groups

Purpose

Drowsiness is a common cause of severe road accidents. Therefore, numerous drowsiness detection methods were developed and explored in recent years, especially concepts using physiological measurements achieved promising results. Nevertheless, existing systems have some limitations that hinder their use in vehicles. To overcome these limitations, this paper aims to investigate the development of a low-cost, non-invasive drowsiness detection system, using physiological signals obtained from conventional wearable devices.

Design/methodology/approach

Two simulator studies, the first study in a low-level driving simulator (N= 10) to check feasibility and efficiency, and the second study in a high-fidelity driving simulator (N= 30) including two age groups, were conducted. An algorithm was developed to extract features from the heart rate signals and a data set was created by labelling these features according to the identified driver state in the simulator study. Using this data set, binary classifiers were trained and tested using various machine learning algorithms.

Findings

The trained classifiers reached a classification accuracy of 99.9%, which is similar to the results obtained by the studies which used intrusive electrodes to detect ECG. The results revealed that heart rate patterns are sensitive to the drivers’ age, i.e. models trained with data from one age group are not efficient in detecting drowsiness for another age group, suggesting to develop universal driver models with data from different age groups combined with individual driver models.

Originality/value

This work investigated the feasibility of driver drowsiness detection by solely using physiological data from wrist-worn wearable devices, such as smartwatches or fitness trackers that are readily available in the consumer market. It was found that such devices are reliable in drowsiness detection.

Fatigue in patients with vestibular schwannoma

BACKGROUND

Patients with vestibular schwannoma (VS) often complain about tiredness, exhaustion, lack of energy, and strength, but such symptoms of fatigue have scarcely been objectified and analyzed in a VS population. We aimed to characterize fatigue in a cohort of patients with VS and compare such symptoms with a control group.

METHODS

All patients who attended an educational course for patients with VS were surveyed with validated tools for assessment of fatigue (fatigue severity scale), anxiety and depression (hospital anxiety and depression scale), sleepiness (Epworth sleepiness scale), and apathy (Starkstein apathy scale). Quality of Life was assessed with the disease-specific Penn Acoustic Neuroma Quality of Life (PANQOL). Symptom severity was estimated with a visual analog scale (VAS). The results have been compared to a control group consisting of patient companions.

RESULTS

Data from 88 VS patients and 49 controls were analyzed. The controls had similar age and sex distribution as patients. Fifty-seven percent of VS patients had significant fatigue, compared to 25% in the control group. The mean fatigue score was 4.1 for the patients, and 2.8 for controls. Patients with fatigue were more likely to have depression, anxiety, sleepiness, and apathy. No correlation of fatigue was found with age, gender, or treatment modality. Regression analyses revealed depression, apathy, and vertigo to be predictors of fatigue. Fatigue was strongly correlated to QoL.

CONCLUSION

Almost six out of ten VS patients had fatigue, significantly higher than the control group. Interest and focus on fatigue in VS patients can improve the patient's QoL.

Domiciliary use of transcutaneous electrical stimulation for patients with obstructive sleep apnoea: a conceptual framework for the TESLA home programme

Obstructive sleep apnoea (OSA) is a global health problem of increasing prevalence. Effective treatments are available with continuous positive airway pressure (CPAP) therapy and mandibular advancement devices (MAD). However, there is limited long-term adherence to therapy, as CPAP and MAD require permanent usage to avoid recurrence of the symptoms and adverse ill health. Alternative treatments would aid in the treatment cascade to manage OSA effectively whenever standard therapy has been trialled and failed. Hypoglossal nerve stimulation (HNS), an invasive approach to stimulate the pharyngeal dilator muscles of the upper airway during sleep, has been approved for the treatment of OSA by several healthcare systems in recent years. In parallel to the development of HNS, a non-invasive approach has been developed to deliver electrical stimulation. Transcutaneous electrical stimulation in obstructive sleep apnoea (TESLA) uses non-invasive electrical stimulation to increase neuromuscular tone of the upper airway dilator muscles of patients with OSA during sleep. Data from previous feasibility studies and randomised controlled trials have helped to identify a subgroup of patients who are "responders" to this treatment. However, further investigations are required to assess usability, functionality and task accomplishment of this novel treatment. Consideration of these factors in the study design of future clinical trials will strengthen research methodology and protocols, improve patient related outcome measures and assessments, to optimise this emerging therapeutical option. In this review, we will introduce a conceptual framework for the TESLA home programme highlighting qualitative aspects and outcomes.

Working Time Society consensus statements: Prescriptive rule sets and risk management-based approaches for the management of fatigue-related risk in working time arrangements

Traditionally, working time arrangements to limit fatigue-related risk have taken a prescriptive approach, which sets maximum shift durations in order to prevent excessive buildup of fatigue (and the associated increased risk) within shifts and sets minimum break durations to allow adequate time for rest and recovery within and/or between shifts. Prescriptive rule sets can be successful when, from a fatigue-related risk standpoint, they classify safe work hours as permitted and unsafe work hours as not permitted. However, prescriptive rule sets ignore important aspects of the biological factors (such as the interaction between circadian and homeostatic processes) that drive fatigue, which are critical modulators of the relationship between work hours and fatigue-related risk. As such, in around-the-clock operations when people must work outside of normal daytime hours, the relationship between regulatory compliance and safety tends to break down, and thus these rule sets become less effective. To address this issue, risk management-based approaches have been designed to regulate the procedures associated with managing fatigue-related risk. These risk management-based approaches are suitable for nighttime operations and a variety of other non-standard work schedules, and can be tailored to the particular job or industry. Although the purpose of these fatigue risk management approaches is to curb fatigue risk, fatigue risk cannot be measured directly. Thus, the goal is not on regulating fatigue risk per se, but rather to put in place procedures that serve to address fatigue before, during, and after potential fatigue-related incidents. Examples include predictive mathematical modeling of fatigue for work scheduling, proactive fatigue monitoring in the workplace, and reactive post-incident follow-up. With different risks and different needs across industries, there is no "one size fits all" approach to managing fatigue-related risk. However, hybrid strategies combining prescriptive rule sets and risk management-based approaches can create the flexibility necessary to reduce fatigue-related risk based on the specific needs of different work environments while maintaining appropriate regulatory oversight.

Sleep extension reduces fatigue in healthy, normally-sleeping young adults

Objective

To assess the effects of one week of sleep extension on mood, fatigue and subjective sleepiness in normal-sleeping young adults.

Methods

Twenty-seven adults (age 24.4±5.4 years, 11 female) participated. At-home baseline sleep/wake patterns were recorded with wrist actigraphy for 14 days. This was followed by two nights of in-lab baseline sleep with 8 hours time in bed (TIB), then 7 nights with TIB extended to 10 hours (2100-0700 hours). Fatigue, mood, and sleepiness were assessed following the 2^nd and 9^th nights of in-laboratory sleep (i.e., 2 nights with 8hTIB and 7 nights with 10 hours TIB, respectively) using the Automated Neuropsychological Assessment Metric and Karolinska Sleepiness Scale. Paired t-tests were used to compare mood, fatigue, and sleepiness ratings between conditions.

Results

At-home wrist actigraphy revealed a mean nightly total sleep time (TST) of 7.53 +/- 0.88 hours of sleep per night. Mean in-lab baseline sleep duration (7.76 +/- 0.59) did not differ from at-home sleep. However, during sleep extension, mean TST was 9.36 +/- 0.37 hours per night, significantly more than during the in-lab baseline (p < .001). Following sleep extension, fatigue ratings were significantly reduced, relative to baseline (p = .03). However, sleep extension had no other significant effects on subjective ratings of mood or sleepiness.

Conclusions

Sleep extension resulted in reduced fatigue in healthy, normal-sleeping young adults, although subjective sleepiness and mood were not improved. Implications include the possibility that (a) the effects of sleep extension on various aspects of mood depend upon the extent to which those aspects of mood are made salient by the study design and methodology; and (b) sleep extension may prove beneficial to fatigue-related conditions such as “burnout.”

Psychometric analysis of Epworth Sleepiness Scale and its correlation with Pittsburgh sleep quality index in poor sleepers among Indian university students

Background The Epworth Sleepiness Scale (ESS) is an 8-item scale to detect excessive daytime sleepiness. Although its psychometric properties are well established on a number of populations the same has not been done for an Indian population, hence this study was designed to cover this knowledge gap. Aims The purpose of this study was to establish the test-retest reliability, validity and internal consistency of the ESS and its correlation with the Pittsburgh Sleep Quality Index (PSQI) in poor sleepers in India. Materials and methods Twenty-five poor sleepers were randomly chosen from a university population. All the subjects were administered the two scales on the test day and the same was repeated after 1 week, which was the retest. Statistical analysis Intraclass coefficient (ICC) and standard error of measurement (SEM) were calculated for the reliability which was further supported by the Bland-Altman graph and a scatterplot. Cronbach's alpha and Pearson's coefficient were calculated for internal consistency and correlation, respectively. Results Twenty-five poor sleepers with mean age 25.24 ± 7.04 years were recruited. The test-retest reliability for ESS displayed good reliability (ICC2,1: 0.86) which was supported by the Bland-Altman graph and the scatterplot. Cronbach's alpha was reported as 0.86 and Pearson's coefficient was r: 0.62, p-value: 0.001. Conclusion The results suggest that the ESS has good internal consistency and test-retest reliability for a university population of poor sleepers in India.

The psycho-sensory wake drive-a power source for power naps and other common sleep-wake phenomena: a hypothesis

Power naps are extensively practiced worldwide and there exists ample documentation of their efficacy in reversing daytime sleepiness. The source of their efficacy, however, as well as the cause and manifestation of many other common sleep-wake phenomena, cannot be entirely explained by the most commonly accepted model of sleep-wake regulation, the two-process model of Borbély, which considers the drives of the circadian and homeostatic sleep processes only. When considering the causes and manifestations of these unexplained phenomena, there appears to be evidence of a wake-promoting drive that is independent of the circadian oscillator indicated in the two-process model of sleep-wake regulation. Although this posited secondary wake drive, herein referred to as the psycho-sensory wake drive, is always active during the awake state, its strength unpredictably varies during a normal day and, therefore, cannot be incorporated into the prevalent two-process model by any current mathematical formula. However, a supplemental graphic model superimposing it on the drives of Process S and Process C can provides plausible and parsimonious explanations for many otherwise unexplainable sleep-wake phenomena and enables rational guidelines for their effective practical management.

Assessment of Wakefulness and Brain Arousal Regulation in Psychiatric Research

During the last few decades, much knowledge has been gained about sleep being a heterogeneous condition with several distinct sleep stages that represent fundamentally different physiological states. The same applies for the wake state which also comprises distinct global functional states (called vigilance stages). However, various terms and concepts have been introduced describing different aspects of wakefulness, and accordingly several methods of assessment exist, e.g. sleep laboratory assessments (Multiple Sleep Latency Test, Maintenance of Wakefulness Test), questionnaires (Epworth Sleepiness Scale, Karolinska Sleepiness Scale), behavioural tasks (Psychomotor Vigilance Test) or electroencephalography (EEG)-based assessments (Alpha Attenuation Test, Karolinska Drowsiness Test). Furthermore, several theoretical concepts about the regulation of sleep and wakefulness have been put forward, and physiological correlates have been identified. Most relevant for healthy functioning is the regulation of brain arousal and the adaption of wakefulness to the environmental and situational needs so that the optimal balance between energy conservation and responsiveness can be obtained. Since one approach to the assessment of brain arousal regulation is the classification of EEG vigilance stages, a computer-based algorithm (Vigilance Algorithm Leipzig) has been introduced, allowing classification of EEG vigilance stages in EEG recordings under resting conditions. The time course of EEG vigilance stages in EEGs of 15-20 min duration allows estimation of the individual arousal regulation (hyperstable, adaptive, or unstable vigilance pattern). The vigilance model of affective disorders and attention-deficit/hyperactivity disorder links a disturbed arousal regulation to the pathogenesis of psychiatric disorders and accordingly helps to explain and possibly also predict treatment effects of pharmacological and non-pharmacological interventions for these conditions.

Tired of blunt tools? Sharpening the clinical assessment of fatigue and sleepiness

Fatigue and sleepiness are ubiquitous symptoms in various conditions and are frequently associated to impaired sleep quality. While separate fatigue and sleepiness scales exist, both constructs are often confused. Unraveling this issue requires estimating the instruments' measurement properties, potential scale recalibration and re-evaluation of symptom intensities on a comparable basis. This study aims at improving the assessment of these symptoms and quantifying their degree of overlap using common-person-equating (CPE). One hundred fifty-nine patients, either with complaints of fatigue, sleepiness and/or non-restorative sleep, addressed to an academic sleep unit for a full-night polysomnography (PSG), enrolled in the study. Symptom levels were measured with the Fatigue Severity (FSS) and Epworth Sleepiness (ESS) scales. Sleep quality was assessed by the Pittsburgh Sleep Quality Index, defining 'good' and 'poor' sleeper groups. Good and poor sleepers did not differ statistically regarding demographics and PSG parameters. Rasch analysis revealed that, considering proper calibration, the ESS and FSS generate reliable and valid, unidimensional linear measures and to be invariant to perceived sleep quality. CPE showed predominantly fatigued, rather than sleepy patients, being more likely to present as poor sleepers. A concordance diagram based on scale scores is provided, in order to improve the differentiation of both symptoms.

Excessive Daytime Sleepiness in Stroke Survivors: An Integrative Review

Excessive daytime sleepiness (EDS) is a prevalent symptom among stroke survivors. This symptom is an independent risk factor for stroke and may reduce stroke survivors' quality of life, cognitive functioning, and daytime functional performance. The lack of a universally accepted definition of EDS makes it difficult to measure EDS and synthesize research. The purpose of this integrative review is to describe poststroke EDS, ascertain conceptual and operational definitions of EDS, identify factors that contribute to EDS in stroke survivors, and explore outcomes associated with EDS in stroke survivors. We searched the following databases: PubMed and MEDLINE (OvidSP 1946-April; Week 2, 2015), Embase (OvidSP 1974-March; Week 1, 2015), and PsycINFO (OvidSP 1967-April; Week 2, 2015). Our search yielded 340 articles, 27 of which met inclusion criteria. The literature reveals EDS to be a multidimensional construct that is operationalized with both subjective and objective measures. Choosing measures that can quantify both the objective and subjective components is useful for gaining a comprehensive understanding of EDS. The antecedents of EDS are stroke, sleep-disordered breathing, reversed Robin Hood syndrome, and depression. The outcomes associated with EDS in stroke patients are serious and negative. Via synthesis of this research, we propose a possible framework for poststroke EDS, which may be of use in clinical practice and in research to identify valid quantifying methods for EDS as well as to prevent harmful outcomes in stroke survivors.

Exhaled nitric oxide from the central airway and alveoli in OSAHS patients: the potential correlations and clinical implications

BACKGROUND

The aim of the study was to evaluate exhaled nitric oxide (eNO) derived from different areas of airway in obstructive sleep apnea hypopnea syndrome (OSAHS) patients with NO exchange model and investigate the potential application and interpretation of eNO in clinical setting.

METHODS

This study was divided into two parts. Firstly, we performed a case control study in 32 OSAHS patients and 27 non-OSAHS participants. Fractional eNO (FeNO) and eNO from the central airway (J'awNO) and from alveoli (CANO) were compared in OSAHS and control groups. Also, correlation of eNO to severity of OSAHS was analyzed. Secondly, a prospective study was conducted in 30 severe OSAHS patients who received a short-term nasal continuous positive airway pressure (nCPAP) treatment. We evaluated eNO, plasma ET-1 concentration, and echocardiography during the treatment process and explored the potential relationship among them.

RESULTS

FeNO and J'awNO were higher in OSAHS and associated with disease severity, while CANO was relatively lower. After nCPAP treatment in severe OSAHS patients, FeNO and J'awNO decreased and CANO increased significantly. Substantial agreement was shown between the elevation of CANO and the decrease of plasma ET-1 concentration after nCPAP by Kappa analysis for consistency. Tei index, which is considered indicative of global right ventricular function, might be predicted by plasma ET-1 levels in severe OSAHS patients.

CONCLUSIONS

NO exchange model provides us with more information of eNO derived from different areas. eNO is not only confirmed to be an effective method for airway inflammation evaluation in the follow-up of OSAHS, CANO may also serve as a useful marker in monitoring endothelial function, resistance of pulmonary circulation, and right ventricular function for clinical implication.

Psychometric properties of the Turkish version of the Sleep Hygiene Index in clinical and non-clinical samples

OBJECTIVE

Sleep is one of the most significant of human behaviors, occupying roughly one third of human life. Sleep is a process the brain requires for proper functioning. Sleep hygiene can be described as practices to ease sleep and to avoid factors which decrease sleep quality. Inadequate sleep hygiene generally results in disturbance of daily life activities due to inability to sustain sleep quality and daytime wakefulness. Therefore, the importance of development and utilization of measures of sleep hygiene increases. The aim of the study was to assess psychometric properties of the Sleep Hygiene Index (SHI) in clinical and non-clinical Turkish samples.

METHOD

Data were collected from 106 patients with major depression consecutively admitted to the psychiatry clinic of Yüzüncü Yıl University School of Medicine and 200 were volunteers recruited from community sample who were enrolled at the university. The SHI, Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI) and Epworth Sleepiness Scale (ESS) were administered to the subjects. Factor structure of the SHI was evaluated with explanatory and multi-sample confirmatory factor analyses. Pearson product-moment correlation coefficients of the SHI with the PSQI, ISI and ESS were computed. Item analyses, internal consistency coefficients and intra-class correlations between two repeated applications in both patient and healthy subjects were calculated.

RESULTS

The SHI revealed a unidimensional factor structure. Significant strong partial associations of the SHI with depression, insomnia and poor sleep quality and a modest partial association with sleepiness were detected. Cronbach's alphas for the SHI in community sample and patients with major depression were 0.70 and 0.71, respectively. Additionally, we found acceptable three-week temporal reliability in terms of intra-correlation coefficients of r=0.62, p<0.01 for the community sample and of r=0.67, p<0.01 among patients with major depression.

CONCLUSION

The SHI revealed adequate validity and reliability to be used by researchers in Turkish sample. Current results were discussed in light of previous findings and theoretical considerations.

Sleeping problems in mothers and fathers of patients suffering from congenital central hypoventilation syndrome

PURPOSE

Advanced medical technology has resulted in an increased survival rate of children suffering from congenital central hypoventilation syndrome. After hospitalization, these technology-dependent patients require special home care for assuring ventilator support and the monitoring of vital parameters mainly during sleep. The daily challenges associated with caring for these children can place primary caregivers under significant stress, especially at night. Our study aimed at investigating how this condition affects mothers and fathers by producing poor sleep quality, high-level diurnal sleepiness, anxiety, and depression.

METHODS

The study included parents of 23 subjects with congenital central hypoventilation syndrome and 23 healthy subjects. All parents filled out the Pittsburgh Sleep Quality Index (PSQI) questionnaire, Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI-II), and Beck Anxiety Inventory (BAI).

RESULTS

A comparison between the two groups showed that parents of patients had poorer sleep quality, greater sleepiness, and higher BDI-II scores compared to that of parents of healthy subjects (respectively, PSQI score 6.5 vs 3.8, ESS score 6.2 vs 4.3, BDI-II score 8.4 vs 5.7). Specifically, mothers of patients showed poorer sleep quality and higher BDI-II scores compared to that of mothers of controls (respectively, PSQI score 7.5 vs 3.8, BDI-II score 9.3 vs 5.9), whereas fathers of patients showed greater levels of sleepiness with respect to fathers of healthy children (respectively, ESS score 6.8 vs 4.0). These differences emerged in parents of younger children.

CONCLUSIONS

Congenital central hypoventilation syndrome impacts the family with different consequences for mothers and fathers. Indeed, while the patients' sleep is safeguarded, sleeping problems may occur in primary caregivers often associated with other psychological disorders. Specifically, this disease affects sleep quality and mood in the mothers and sleepiness levels in the fathers.

Non-REM sleep EEG power distribution in fatigue and sleepiness

OBJECTIVES

The aim of this study is to contribute to the sleep-related differentiation between daytime fatigue and sleepiness.

METHODS

135 subjects presenting with sleep apnea-hypopnea syndrome (SAHS, n=58) or chronic fatigue syndrome (CFS, n=52) with respective sleepiness or fatigue complaints and a control group (n=25) underwent polysomnography and psychometric assessments for fatigue, sleepiness, affective symptoms and perceived sleep quality. Sleep EEG spectral analysis for ultra slow, delta, theta, alpha, sigma and beta power bands was performed on frontal, central and occipital derivations.

RESULTS

Patient groups presented with impaired subjective sleep quality and higher affective symptom intensity. CFS patients presented with highest fatigue and SAHS patients with highest sleepiness levels. All groups showed similar total sleep time. Subject groups mainly differed in sleep efficiency, wake after sleep onset, duration of light sleep (N1, N2) and slow wave sleep, as well as in sleep fragmentation and respiratory disturbance. Relative non-REM sleep power spectra distributions suggest a pattern of power exchange in higher frequency bands at the expense of central ultra slow power in CFS patients during all non-REM stages. In SAHS patients, however, we found an opposite pattern at occipital sites during N1 and N2.

CONCLUSIONS

Slow wave activity presents as a crossroad of fatigue and sleepiness with, however, different spectral power band distributions during non-REM sleep. The homeostatic function of sleep might be compromised in CFS patients and could explain why, in contrast to sleepiness, fatigue does not resolve with sleep in these patients. The present findings thus contribute to the differentiation of both phenomena.

State-trait arousal and daytime sleepiness after sleep restriction

The importance of an arousal system in the regulation of sleepiness has been widely recognised in contexts of insomnia theory and research. Arousal is also incorporated in some general models of sleepiness and is considered one of the principal factors regulating sleepiness in a model by De Valck and Cluydts (2003), in which arousal has both state and trait components. In the present experimental study, we explored the effects of state and trait components of arousal on subjective sleepiness and sleep latency during daytime. On a day after partial sleep deprivation, 28 good sleepers aged 18-26 years took part in two successive experimental conditions, in which the state arousal was manipulated by laboratory tasks. We measured physiological (heart rate, frequency of skin conductance responses) and subjective (Energy, Tension, Anxiety) indices of state arousal, while trait arousal was operationalised as electrodermal lability. After a moderately stressful task, which induced a relatively higher state arousal, the participants reported lower sleepiness and took longer to fall asleep than after a simple psychomotor task. Trait arousal was not associated with daytime sleepiness. The results of this study support the idea that short-term changes of state arousal are important for the regulation of sleepiness in good sleepers, even in a situation which is only moderately stressful.

Regulation of sleepiness: the role of the arousal system

Sleepiness is a widespread phenomenon in the busy industrial countries, and many studies have identified its significant negative impacts on individuals and society. Particularly important are the data that associate sleepiness with the risk of accidents at workplace and in transport, pointing to shift workers as the most vulnerable population. It is generally accepted that two basic physiological processes regulate sleepiness: homeostatic and circadian rhythmic processes. Recent research has proposed the third component regulating sleepiness, that is, the wake drive or the arousal system. The role of the arousal system in regulating sleepiness has partly been addressed by the studies of the pathophysiology of insomnia, which is often described as a disorder of hyperarousal. Experimental and correlational studies on the relation between sleepiness and arousal in good sleepers have generally indicated that both physiological and cognitive arousal are related to the standard measures of sleepiness. Taking into account the role of the arousal system in regulating sleepiness widens the possibilities for the management of sleep disorders and could also help in solving the problem of excessive sleepiness at work and the wheel.

[Review on sleep and awakening disorders]

Insomnia is the most prevalent sleep disorders and affects severely 10% of adults worldwide. From poor sleep to insomnia, the severity of sleep disorders should be assessed clinically and by the use of validated questionnaires based on international consensual definitions. One main sign of insomnia is impaired daytime functioning. Insomnia may be treated with hypnotics only for a limited duration. Behavioural and cognitive therapies have been found efficient on chronic insomnia. Sleepiness is also a common sleep disorders due to altered sleep schedules, sleep deprivation, sleep disorders or as an adverse effect of some treatments. The risk of car accidents and the impaired quality of daytime functioning are the main consequences of sleepiness. The aim of this paper is to give some recommendations for the diagnosis and treatment of insomnia and sleepiness.

Case-control study on the association between qi-stagnation and insomnia

OBJECTIVE

To investigate the relationship between insomnia and qi-stagnation by using the international standardized measurement of sleep quality and the Traditional Chinese Medicine (TCM) Constitution Scales.

METHODS

A survey by means of the TCM Constitution Scales, the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and the Deep Sleep Scale (DSS) in 169 participants aged between 16 and 80 years old was conducted. Comparison was made to examine the sleep quality and insomnia symptoms in the qi-stagnation group and other-constitution group.

RESULTS

Univariate analysis found that the qi-stagnation group had a significantly increased risk of difficulty in falling asleep (OR=3.012, and 95% CI 1.310 to 6.923 for PSQI; OR=3.016, and 95% CI 1.358 to 6.709 for DSS) and early waking (OR=3.545, and 95% CI 1.229 to 10.232 for PSQI; OR=2.742, and 95% CI 1.072 to 7.014 for DSS), while the other-constitution group had a significant risk of dreaminess (OR=2.419, and 95% CI 1.154 to 5.072 for PSQI; OR=2.561, and 95% CI 1.116 to 5.880 for DSS). A dose-effect relationship existed between insomnia symptoms and qi-stagnation. Qi-stagnation significantly increased the risk of difficulty in falling asleep and early waking.

CONCLUSION

This case-control study revealed that there is a statistically significant association between qi-stagnation and insomnia. Based on this study, we recommend that further research should be conducted for the rehabilitative care and cure of insomnia from the perspective of TCM constitution.

Repeating administration of Epworth Sleepiness Scale is clinically useful

PURPOSE

We aimed to verify whether it is clinically useful to repeat the Epworth Sleepiness Scale (ESS) in individuals with suspected sleep-disordered breathing (SDB).

METHODS

In this cross-sectional, prospective study, results of the repeated administration of the ESS were analyzed. In 929 consecutive patients, ESS was obtained as usual in the laboratory routine, immediately before the sleep study (ESS1) and was repeated in the morning, after the polysomnography (ESS2). ROC curve, classical psychometry, and item response theory (IRT) Rasch analysis were used to assess measurement properties of ESS.

RESULTS

The ESS1 score was (mean ± SD), 11 ± 5.1, and the ESS2, 13 ± 4.7 (p < 0.001). Change in ESS score is explained in multivariate analysis by age, but not by gender, educational level, change in Stanford Sleepiness Scale, symptoms of sleep disorder, or polysomnography results. Accuracy of an ESS score >10 to predict apnea-hypopnea index ≥5 increased from 56% (ESS1) to 72% (ESS2). IRT psychometric properties (unidimensionality, invariance, local independence) were maintained in ESS2.

CONCLUSIONS

Repeating the administration of the Epworth Sleepiness Scale in a clinical setting increases its score and diagnostic accuracy and correlation with SDB variables, without changing the psychometric properties of the scale. This experiment indicates the clinical usefulness of repeating the ESS. The scale can be repeated at a negligible cost, before dismissing individual patients on the basis of a low ESS score, discontinuing a potentially lifesaving diagnostic and therapeutic process.

Fatigue, sleepiness, and physical activity in patients with multiple sclerosis

Fatigue is a frequent and disabling symptom in patients with multiple sclerosis (MS). The objective of the study was to compare fatigue and sleepiness in MS, and their relationship to physical activity. Eighty patients with MS rated the extent of experienced fatigue (Fatigue Severity Scale, FSS) and sleepiness (Epworth Sleepiness Scale, ESS). The relationship between the scales was analysed for the scales as a whole and for single items. The clinical status of the patients was measured with the Extended Disability Status Scale (EDSS). In addition, physical activity was recorded continuously for 1 week by wrist actigraphy. The mean scores of fatigue and sleepiness were significantly correlated (FSS vs. ESS r=0.42). Single item analysis suggests that fatigue and sleepiness converge for situations that demand self-paced activation, while they differ for situations in which external cues contribute to the level of activation. While fatigue correlated significantly with age (r=0.40), disease severity (EDSS, r=0.38), and disease duration (r=0.25), this was not the case for sleepiness. Single patient analysis showed a larger scatter of sleepiness scores in fatigued patients (FSS>4) than in non-fatigued patients. Probably, there is a subgroup of MS patients with sleep disturbances that rate high on ESS and FSS. The amount of physical activity, which was measured actigraphically, decreased with disease severity (EDSS) while it did not correlate with fatigue or sleepiness.

Sleepiness, quality of life, and sleep maintenance in REM versus non-REM sleep-disordered breathing

RATIONALE

The impact of REM-predominant sleep-disordered breathing (SDB) on sleepiness, quality of life (QOL), and sleep maintenance is uncertain.

OBJECTIVE

To evaluate the association of SDB during REM sleep with daytime sleepiness, health-related QOL, and difficulty maintaining sleep, in comparison to their association with SDB during non-REM sleep in a community-based cohort.

METHODS

Cross-sectional analysis of 5,649 Sleep Heart Health Study participants (mean age 62.5 [SD = 10.9], 52.6% women, 22.6% ethnic minorities). SDB during REM and non-REM sleep was quantified using polysomnographically derived apnea-hypopnea index in REM (AHI(REM)) and non-REM (AHI(NREM)) sleep. Sleepiness, sleep maintenance, and QOL were respectively quantified using the Epworth Sleepiness Scale (ESS), the Sleep Heart Health Study Sleep Habit Questionnaire, and the physical and mental composites scales of the Medical Outcomes Study Short Form (SF)-36.

MEASUREMENTS AND MAIN RESULTS

AHI(REM) was not associated with the ESS scores or the physical and mental components scales scores of the SF-36 after adjusting for demographics, body mass index, and AHI(NREM) x AHI(REM) was not associated with frequent difficulty maintaining sleep or early awakening from sleep. AHI(NREM) was associated with the ESS score (beta = 0.25; 95% confidence interval [CI], 0.16 to 0.34) and the physical (beta = -0.12; 95% CI, -0.42 to -0.01) and mental (beta = -0.20; 95% CI, -0.20 to -0.01) components scores of the SF-36 adjusting for demographics, body mass index, and AHI(REM).

CONCLUSIONS

In a community-based sample of middle-aged and older adults, REM-predominant SDB is not independently associated with daytime sleepiness, impaired health-related QOL, or self-reported sleep disruption.

Evaluation of general psychopathology, subjective sleep quality, and health-related quality of life in patients with obesity

OBJECTIVE

Recently, the increasing rate of obesity has been elucidated as a major public health problem. The aim of this study was to examine the psychological distress, subjective sleep quality, and health-related quality of life (HRQOL) in a group of patients diagnosed with obesity.

METHODS

A total of 124 obese patients (32 of them Class I obesity (BMI: 30-34.9 kg/m2), 92 Class II obesity (BMI: > or = 35kg/m2)) and 106 healthy control subjects were involved in the study. Subjects were evaluated with self-administered questionnaires including the Symptoms Checklist-90-Revised (SCL-90-R), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Short Form 36 (SF-36). Several clinical and socio-demographic data were also recorded.

RESULTS

Class II obesity group had a significantly worse psychological status, quality of life, and sleep quality than control group, Although Class I obesity group did not differ from Class II and control groups according to sleep quality and psychological status, they had worse HRQOL than the control group. BMI scores positively correlated with the majority of subscales of psychological distress (SCL-90-R) and sleep quality (PSQI, ESS) and negatively correlated with all dimensions of HRQOL (SF-36).

CONCLUSIONS

Obesity is associated with psychological distress, poor sleep quality, and reduced quality of life. Thus, obesity should be evaluated in a biopsychosocial manner, including management of patients' psychopathology.

The Time of Day Sleepiness Scale to assess differential levels of sleepiness across the day

OBJECTIVE

The study evaluated the Time of Day Sleepiness Scale (ToDSS) to determine subjective estimates of sleepiness in the morning, afternoon, and evening. Scores on the ToDSS were compared to the Epworth Sleepiness Scale (ESS). The ToDSS was evaluated on three cohorts of patients at a sleep medicine clinic.

METHOD

The items of the ToDSS are modified from the ESS to enable subjective assessment in the morning (before noon), afternoon (noon to 1800 h), and evening (after 1800 h). The scale takes about 5 min to complete. For each item, patients provide an estimate of their level of sleepiness in three separate columns, each indicating the time of day (morning, afternoon, and evening).

RESULTS

Each ToDSS score evidenced a one factor structure. The ToDSS enabled the assessment of differential levels of sleepiness across the day among several cohorts, with scores increasing in the afternoon and evening. The ESS and each score of the ToDSS demonstrated high correlations. Lower subjective estimates of sleepiness were documented after treatment with continuous positive airway pressure.

CONCLUSIONS

The ToDSS was shown to have comparable psychometric features to the ESS and provided perceived sleepiness levels across the day in an efficient and cost-effective manner. It also enabled characterization of treatment response among a cohort of patients with obstructive sleep apnea.

Dimensions of sleepiness and their correlations with sleep-disordered breathing in mild sleep apnea

OBJECTIVE: There are many ways of assessing sleepiness, which has many dimensions. In patients presenting a borderline apnea-hypopnea index (AHI, expressed as events/hour of sleep), the mechanisms of excessive daytime sleepiness (EDS) remain only partially understood. In the initial stages of sleep-disordered breathing, the AHI might be related to as-yet-unexplored EDS dimensions. METHODS: We reviewed the polysomnography results of 331 patients (52% males). The mean age was 40 ± 13 years, and the mean AHI was 4 ± 2 (range, 0-9). We assessed ten potential dimensions of sleepiness based on polysomnography results and medical histories. RESULTS: The AHI in non-rapid eye movement (NREM) stage 1 sleep (AHI-N1), in NREM stage 2 sleep (AHI-N2), and in REM sleep (AHI-REM) were, respectively, 6 ± 7, 3 ± 3 and 10 ± 4. The AHI-N2 correlated significantly with the greatest number of EDS dimensions (5/10), including the Epworth sleepiness scale score (r = 0.216, p < 0.001). Factor analysis, using Cronbach's alpha, reduced the variables to three relevant factors: QUESTIONNAIRE (α = 0.7); POLYSOMNOGRAPHY (α = 0.68); and COMPLAINTS (α = 0.55). We used these factors as dependent variables in a stepwise multiple regression analysis, adjusting for age, gender, and body mass index. The AHI-N1 correlated significantly with POLYSOMNOGRAPHY (β = -0.173, p = 0.003), and the AHI-N2 correlated significantly with COMPLAINTS (β = -0.152, p = 0.017). The AHI-REM did not correlate with any factor. CONCLUSIONS: Our results underscore the multidimensionality of EDS in mild sleep apnea.

Sleep length and quality, sleepiness and urinary melatonin among healthy Danish nurses with shift work during work and leisure time

BACKGROUND

Sleep problems are common effects of shift work. The aim of the present study was to evaluate how different types of shift affect sleep and sleepiness, and to relate sleepiness to urinary 6-sulfatoxymelatonin.

METHODS

A total of 166 volunteer healthy Danish nurses working day, evening, or night, respectively fixed and mixed schedules were included. Self-reports of sleep were assessed together with real-time sleepiness and spot urine samples analyzed for 6-sulfatoxymelatonin on a workday and a leisure day.

RESULTS

On a day off the nurses slept longer, with a better quality and reported less sleepiness compared to a workday. Nurses on nightshift reported poorer sleep quality than nurses on other shifts. Sleepiness was highest for nurses on mixed schedules. Concentrations of urinary 6-sulfatoxymelatonin and sleepiness were generally correlated except for nurses working fixed nights.

CONCLUSIONS

The poorest sleep quality was observed for nurses in mixed schedules working nights. The lack of correlation between sleepiness and 6-sulfatoxymelatonin on mixed night shift may indicate that the influence of endogenous melatonin is limited.