Sleep assessment using EEG-based wearables - A systematic review

Polysomnography (PSG) is the reference standard of sleep measurement, but is burdensome for the participant and labor intensive. Affordable electroencephalography (EEG)-based wearables are easy to use and are gaining popularity, yet selecting the most suitable device is a challenge for clinicians and researchers. In this systematic review, we aim to provide a comprehensive overview of available EEG-based wearables to measure human sleep. For each wearable, an overview will be provided regarding validated population and reported measurement properties. A systematic search was conducted in the databases OVID MEDLINE, Embase.com and CINAHL. A machine learning algorithm (ASReview) was utilized to screen titles and abstracts for eligibility. In total, 60 papers were selected, covering 34 unique EEG-based wearables. Feasibility studies indicated good tolerance, high compliance, and success rates. The 42 included validation studies were conducted across diverse populations and showed consistently high accuracy in sleep staging detection. Therefore, the recent advancements in EEG-based wearables show great promise as alternative for PSG and for at-home sleep monitoring. Users should consider factors like user-friendliness, comfort, and costs, as these devices vary in features and pricing, impacting their suitability for individual needs.

Wearable and mobile technology to characterize daily patterns of sleep, stress, presleep worry, and mood in adolescent insomnia

OBJECTIVES

Characterizing daily patterns of sleep, stress, presleep worry, and mood in adolescents with and without insomnia symptomatology.

DESIGN

Two months of continuous wearable tracking and daily diary ratings.

SETTING

Free-living conditions.

PARTICIPANTS

Ninety-three adolescents (59 girls; 16-19 years old) with (N = 47; 26 with clinical and 21 with sub-clinical) and without (N = 46; control) DSM-5 insomnia symptomatology.

MEASUREMENTS

Fitbit Charge 3 tracked sleep, heart rate, and steps. Evening electronic diaries collected ratings of daily stress, presleep worry, and mood.

RESULTS

While sleep duration (control: 6.88 ± 1.41 hours; insomnia: 6.92 ± 1.28 hours), architecture, timing, and night-to-night variability were similar between groups, the insomnia group reported higher levels of stress and worry, being mainly related to "school". At the intraindividual level, stress and worry predicted shorter sleep duration and earlier wake up times, which, in turn, predicted higher stress the following day. Moreover, higher-than-usual stress predicted higher sleep-time heart rate, with a more consistent effect in adolescents with insomnia. Results were overall consistent after controlling for covariates and several robustness checks.

CONCLUSIONS

There is a bidirectional relationship between daily stress and sleep, with daily stress negatively impacting sleep, which in turn leads to more stress in adolescents with and without insomnia symptoms. Findings also highlight the complexity of insomnia in adolescence, in which the core clinical features (perceived sleep difficulties) and the critical factors (stress/worry) implicated in the pathophysiology of the disorder are not necessarily reflected in objective sleep indicators.

Sleep, Aging, and Daily Functioning

Older adults who do not sleep well frequently have difficulty sustaining attention, display slower physical response times, and have memory issues that may contribute to depression or early dementia. The life changes that accompany aging, such as retirement, bereavement, or the onset of chronic illness or disability, can precipitate sleep problems. Insomnia and obstructive sleep apnea are the most common sleep disorders in older adults and can have far-reaching consequences on health and well-being. Nurses should include thorough sleep assessments in any patient interview.

ISI-3: evaluation of a brief screening tool for insomnia

STUDY OBJECTIVES

We evaluated the performance of the Insomnia Severity Index-3 (ISI-3) as a short screening tool to identify clinically significant insomnia derived from the 7-item ISI in an older primary care population.

METHODS

We used results from two surveys including the 7-item ISI: Sample 1 (n = 3197) and Sample 2 (n = 247) individuals aged ≥60 years with a diagnosis of osteoarthritis from electronic health records. The 7 items were: difficulty falling asleep, difficulty staying asleep, waking too early, sleep satisfaction, sleep interference with daytime functioning, noticeability of sleep problems by others, and worry about sleep. The ISI-3 included items with highest item-total correlations to the 7-item ISI from Sample 1. A 7-item ISI score ≥15 was defined as clinically significant insomnia and served as the primary criterion for the ISI-3. We derived operating characteristics to determine the diagnostic accuracy and cut-points to maximize sensitivity and specificity for both samples.

RESULTS

The items with the highest item-total correlations were: sleep dissatisfaction, sleep interference with daily functioning, and worry about sleep problems (r = 0.78-0.81); while difficulty falling asleep, difficulty staying asleep, waking too early and noticeability of sleep problems by others showed lower correlations (r = 0.60-0.74). The ISI-3 achieved high discriminant validity in identifying insomnia (AUC = 0.97-0.98). An ISI-3 score of ≥7 maximized sensitivity (0.94-0.97) and specificity (0.88-0.91) with kappa = 0.68-0.71, 89.1-91.5% agreement.

CONCLUSIONS

The ISI-3 can effectively screen for insomnia to trigger a more thorough diagnostic evaluation including the 7-item ISI for research or clinical purposes. Future validation studies are needed in other community and clinical populations.

CLINICAL TRIAL

This manuscript describes secondary analyses of data two National Institutes on Aging-funded clinical trials (ClinicalTrials.gov identifier: NCT01142349, NCT02946957).

Sleep Assessment for Sleep Problems in Children

The breadth of childhood sleep problems is broad and can be associated with biologic, psychiatric, behavioral, social, and environmental processes. Unrecognized childhood sleep problems may threaten daytime behaviors and negatively impact school and psychosocial functioning. Left unattended, overall child biopsychosocial development may be impaired. Thus, identifying and addressing sleep problems has potential to optimize childhood health, development, and overall well-being. Nurses need to be cognizant of detrimental impacts of child sleep deprivation and advocate for appropriate sleep assessments while offering sleep education to parents and children.

Assessment and Monitoring of Sleep in the Intensive Care Unit

Sleep affects physiologic and psychological recovery throughout critical illness. Patients often describe poor sleep as a major source of distress while hospitalized in an intensive care unit. The intensive care unit environment poses unique challenges for sleep assessment and monitoring. The purpose of this literature review is to discuss methods of assessment and monitoring of sleep within the intensive care unit setting. The advantages and disadvantages of physiologic monitoring of sleep (eg, polysomnography, bispectral index, and actigraphy) are compared with those of subjective measures of sleep quality (eg, validated patient-oriented sleep questionnaires, and informal nursing assessments).

Use of actigraphy and sleep diaries to assess sleep and academic performance in pharmacy students

INTRODUCTION

Sleep parameters have been shown to correlate with academic performance. Current studies assessing sleep in doctor of pharmacy (PharmD) students rely on self-reported sleep parameters and academic performance. The objectives of this study were to describe and compare sleep parameters in pharmacy students using actigraphy and sleep diaries and to assess the correlation of sleep parameters with academic performance.

METHODS

This prospective cohort study with convenience sampling assessed sleep parameters in pharmacy students. Thirty-five students completing the second year of a PharmD program participated in the study. Participants wore actigraph watches and maintained sleep diaries for seven consecutive days during the spring and fall semesters, while classes were in session, except for one week prior to exams and the week of exams. Academic performance was tracked during fall and spring semesters.

RESULTS

Actigraphy and sleep diaries showed significant differences in sleep latency (SL), actual sleep time (AST), wake bouts, and sleep efficiency (SE). Actigraphy results indicated that the participants fell asleep faster (SL), slept a shorter duration (AST), had more wake bouts, and lower SE than results reported in the sleep diaries. SE and SL from the sleep diaries positively correlated with the fall semester pharmaceutical sciences course and overall spring semester academic performance. Actigraphy recorded AST correlated with performance in both semesters' clinical sciences courses.

CONCLUSIONS

The results of actigraphy differed from the sleep diaries. More studies are needed to assess differences in detection of sleep parameters using sleep diaries and actigraphs.

Systematic review of clinical practice guidelines to identify recommendations for sleep in type 2 diabetes mellitus management

INTRODUCTION

Sleep quality, quantity and timing have been shown to impact glycaemic control, with a role in insulin sensitivity, glucose tolerance and HbA1C levels, in both diabetic and non-diabetic populations. The aim of this study was to identify recommendations for sleep assessment and management in international clinical practice guidelines focused on type 2 diabetes mellitus management in adults.

STUDY DESIGN

Systematic Review.

METHODOLOGY

Clinical practice guidelines which focused on the management of type 2 diabetes mellitus in adults were included (n = 35). Two independent reviewers utilised the Appraisal of Guidelines for Research and Evaluation tool (AGREE) II and a third reviewer resolved any disagreements. Included guidelines were assessed for recommendations about sleep in diabetes management (n = 14). Data were extracted on sleep recommendations ,themes were generated from the extracted data and narrative syntheses were created.

RESULTS

From 1114 identified papers, 35 guidelines met the inclusion criteria. Fourteen of these guidelines included recommendations pertaining to sleep, which broadly fell into five categories; sleep assessment, sleep as a therapeutic target, sleep and co-morbidities of type 2 diabetes mellitus, shift work and sleep and driving. Recommendations varied across guidelines.

CONCLUSION

Few guidelines provided recommendations relating to assessment and management of sleep in type 2 diabetes care. Most of the recommendations were related to obstructive sleep apnoea. However, few guidelines discussed sleep as a therapeutic intervention for diabetes mellitus or described the potential importance of sleep quality and duration in glycaemic control. Prospero registration number: CRD42020142136.

Prevalence of obstructive sleep apnoea in acute coronary syndrome patients: systematic review and meta-analysis

Background

Obstructive Sleep Apnoea (OSA) has been recognised as a risk factor for cardiovascular diseases such as hypertension and cardiovascular events such as acute coronary syndrome (ACS). Since it is also known to reduce exercise tolerance, it is important to establish the prevalence of OSA in ACS patients, particularly in those who are commencing cardiac rehabilitation (CR) programs.

Methods

Using PRISMA guidelines a systematic search was conducted in order to identify studies that objectively measured (using polysomnography or portable monitoring) the prevalence of OSA in ACS patients following hospital admission. A data extraction table was used to summarise study characteristics and the quality of studies were independently assessed using the Joanna Briggs Institute Prevalence Critical Appraisal Tool. Meta-analysis of the selected studies was conducted in order to estimate OSA prevalence as a function of the two main methods of measurement, the severity of OSA, and timing of the OSA assessment following ACS hospital admission.

Results

Pooled prevalence estimates of OSA using the “gold standard” polysomnography ranged from 22% for severe OSA to 70% for mild OSA, at any time after hospital admission. Similar prevalence estimates were obtained using portable monitoring, but interpretation of these results are limited by the significant heterogeneity observed among these studies.

Conclusions

Prevalence of OSA following ACS is high and likely to be problematic upon patient entry into CR programs. Routine screening for OSA upon program entry may be necessary to optimise effectiveness of CR for these patients.

Sleep assessment and interventions for patients living with cancer from the patients' and nurses' perspective

BACKGROUND

Difficulty sleeping is a common symptom for patients living with cancer that significantly affects their lives. However, although sleep disorders are common, it is an overlooked problem in cancer care.

PURPOSE

This study assessed the prevalence of sleep disturbances among patients living with cancer, and assessed the adequacy of sleep assessment and intervention for patients from both nurses' and patients' perspectives.

METHOD

Descriptive, cross-sectional and correlational design was used in this study. A convenience sample of 129 patients with cancer and 113 registered nurses working with cancer patients was recruited. A structured face-to-face interview was used to complete the patients' questionnaires and a self-administered questionnaire was given to nurses.

FINDINGS

The majority of patients with cancer reported having poor sleep quality (69.8%). About 86.7% (n=98) of nurses reported that they have never screened patients with cancer for any sleep problems, and 76.7% (n=99) of the patients reported that they have never been assessed for sleep problems by the nursing staff during hospitalisation. Only 8% of patients with cancer who reported having problems sleeping to a nurse received interventions to promote better sleep.

CONCLUSION

Assessment of sleep disturbances in patients with cancer should be unified using a comprehensive reliable valid instrument, as well as providing evidence-based interventions according to patient's need. A written policy should be introduced to encourage sleep documentation and to make sleep care for patients part of routine nursing care.

Sleep Assessment During Shift Work in Korean Firefighters: A Cross-Sectional Study

Background

This cross-sectional study assessed the sleep quality using the ActiGraph and investigated the relationship between the parameters of sleep assessment and the type of shift work in Korean firefighters.

Methods

The participants were 359 firefighters: 65 day workers (control group) and 294 shift workers (shift work group: 77 firefighters with 3-day shift, 72 firefighters with 6-day shift, 65 firefighters with 9-day shift, and 80 firefighters with 21-day shift). Sleep assessments were performed using the ActiGraph (wGT3X-BT) for 24 hours during day shift (control and shift work group) and night shift and rest day (shift work group). The participants recorded bed time and sleep hours during the measurement period.

Results

Sleep efficiency, total sleep time, and percentage of wake after sleep onset during night work were lower in the shift work group than control group (p < 0.05). Sleep efficiency decreased in night shift and increased in rest day, whereas wake after sleep onset increased in night shift and decreased in rest day (p < 0.05). Among shift work groups, sleep efficiency of 6-day shift was higher in day shift, and sleep efficiency of 21-day shift was lower in night shift than other shift groups (p < 0.05).

Conclusion

We found that the sleep quality in night shift of the shift work group was poorer than the control group. As to the type of shift work, sleep quality was good in 6-day shift and poor in 21-day shift. Thus, fast rotating shift such as 6-day shift may be recommended to improve the sleep quality of the firefighters.

Sleep Deprivation in Intensive Care Unit - Systematic Review

Background

Sleep disturbances in intensive care unit (ICU) patients have been studied worldwide for over 30 years. Factors contributing to sleep disturbances are still being identified, and therapeutic procedures aimed at the mitigation of such ailments are consequently being developed.

Objectives

The aim of this study was to review the literature on sleep disturbances in intensive care unit patients.

Material and Methods

MEDLINE PubMed, OVID, Web of Science, and EBSCO databases have been searched using adequate keywords.

Results

Sleep disorders in ICUs were common among all of the analysed articles. Noise plays a significant role in sleep interruption (11.5 - 17% of awakenings). It was noted that the introduction of "white noise" into the ICU environment proved unsuccessful in reducing the magnitude of changing noise levels. Nursing care activities significantly disturb nocturnal rest, and 42.7 such procedures per every 12-hour night shift were registered. Aggregating nursing care interventions was suggested in order to reduce the number of stimuli experienced by the patient.

Conclusion

Changes in sleep structure developing during an ICU stay may significantly contribute to sleep disorders once the hospitalisation is over.

A survey on sleep assessment methods

Purpose

A literature review is presented that aims to summarize and compare current methods to evaluate sleep.

Methods

Current sleep assessment methods have been classified according to different criteria; e.g., objective (polysomnography, actigraphy…) vs. subjective (sleep questionnaires, diaries…), contact vs. contactless devices, and need for medical assistance vs. self-assessment. A comparison of validation studies is carried out for each method, identifying their sensitivity and specificity reported in the literature. Finally, the state of the market has also been reviewed with respect to customers’ opinions about current sleep apps.

Results

A taxonomy that classifies the sleep detection methods. A description of each method that includes the tendencies of their underlying technologies analyzed in accordance with the literature. A comparison in terms of precision of existing validation studies and reports.

Discussion

In order of accuracy, sleep detection methods may be arranged as follows:

Questionnaire < Sleep diary < Contactless devices < Contact devices < Polysomnography

A literature review suggests that current subjective methods present a sensitivity between 73% and 97.7%, while their specificity ranges in the interval 50%–96%. Objective methods such as actigraphy present a sensibility higher than 90%. However, their specificity is low compared to their sensitivity, being one of the limitations of such technology. Moreover, there are other factors, such as the patient’s perception of her or his sleep, that can be provided only by subjective methods. Therefore, sleep detection methods should be combined to produce a synergy between objective and subjective methods. The review of the market indicates the most valued sleep apps, but it also identifies problems and gaps, e.g., many hardware devices have not been validated and (especially software apps) should be studied before their clinical use.

Clinically relevant cut-off values for the Parkinson's Disease Sleep Scale-2 (PDSS-2): a validation study

BACKGROUND

Sleep disturbances are a major problem encountered by neurologists attending Parkinson's disease (PD) patients. The Parkinson's Disease Sleep Scale-2 (PDSS-2) assesses a wide spectrum of disease-specific sleep problems and is easy to administer as a patient self-rating scale. The validation study showed that the scale is reliable, valid, and precise. Until now, however, only one Japanese study has assessed cut-off scores to define poor sleepers.

OBJECTIVES

In this context we aimed to determine the PDSS-2 cut-off values that define a sleep disturbance severe enough to require referral of the patient to a sleep center or the need for specific treatment.

METHODS

Inpatients with idiopathic PD consecutively admitted to our hospital were enrolled. Patients completed the PDSS-2. The attending physician, who was blinded to the PDSS-2 results, but familiar with the patients' history and current disease status, completed a questionnaire consisting of two general questions on the presence of PD-specific and non-PD related sleep problems. Statistical analysis was performed to determine cut-off values for the PDSS-2 and correlation with the physician's evaluation of sleep disturbance severity. A natural cohort of non-PD patients with sleep disorders represented the control group.

RESULTS

The sample consisted of 52 (56%) men and 41 (44%) women with an average age of 69.22 ± 8.74 years. PDSS-2 showed a sensitivity of 77.6% and a specificity of 74.3% in relation to physician's evaluation of PD-specific sleep problems. According to the physician's evaluation, PD-specific sleep disturbances occurred in 62% of the patients. 83% of patients with PDSS-2 scores ≥18 had clinically relevant sleep disturbances compared to only 33% of PD patients with scores <18. The severity of PD-specific sleep problems was well correlated with the PDSS-2 total score (r = 0.49).

CONCLUSIONS

To our knowledge, this is the first study to define PDSS-2 cut-off values for the severity of sleep disturbances in a European PD sample. Our study shows that scores ≥18 define clinically relevant PD-specific sleep disturbances.