Sleep during COVID-19-related school lockdown, a longitudinal study among high school students

There has been great concern about the impact of coronavirus disease 2019 (COVID-19)-related school lockdown on adolescent health. The aim of the present study was to compare sleep patterns before and during COVID-19-related school lockdown, in a large sample of high school students. The present study is based a prospective, longitudinal survey on adolescent sleep health. Phase 1 was conducted in 2019, whereas phase 2 was conducted in 2020 (response rate 60.2%), during the last 10 days of a 60-day long school lockdown. Main outcomes comprised sleep parameters from the Munich ChronoType Questionnaire (MCTQ). A total of 2,022 students provided valid responses to MCTQ in both survey phases. Results showed later sleep timing on schooldays in 2020 compared to 2019 (36 min later bedtimes, Cohen's d = 0.56; 1:35 hr later rise times, Cohen's d = 1.44). Time spent in bed on schooldays increased from 8:20 to 9:19 hr (Cohen's d = 0.78), and sleep duration increased by 45 min (Cohen's d = 0.49). The proportion of adolescents obtaining the recommended ≥8 hr of sleep on schooldays increased from 13.4% (2019) to 37.5% during the lockdown. Social jetlag was reduced from 2:37 hr (2019) to 1:53 hr (2020, Cohen's d = 0.59). Results points to a potential advantageous effect of school lockdown in terms of increased school day sleep duration and reduced social jetlag. As sleep is important for mental and somatic health, it is conceivable that increased sleep duration offered some protection against harmful aspects of the COVID-19 pandemic and associated social restrictions. Future studies should address possible associations between sleep changes and health during COVID-19-related school lockdown.

How our Dreams Changed During the COVID-19 Pandemic: Effects and Correlates of Dream Recall Frequency - a Multinational Study on 19,355 Adults

OBJECTIVE

Many have reported odd dreams during the pandemic. Given that dreams are associated with mental health, understanding these changes could provide crucial information about wellbeing during the pandemic. This study explored associations between COVID-19 and dream recall frequency (DRF), and related social, health, and mental health factors.

METHODS

We conducted a cross-sectional web survey of 19,355 individuals in 14 countries from May to July 2020. We collected data on COVID-19, mental health, sleep and DRF during the pandemic. We performed McNemar Tests to compare low (<3 nights per week) and high DRF (≥3 nights per week) before and during COVID-19 and to evaluate changes in sleep variables segmented by DRF. Chi-square tests were conducted to compare characteristics between low and high DRF. Logistic regression analyses were conducted to examine associations between various independent variables and DRF.

RESULTS

Reports of high DRF during the pandemic were higher than before the pandemic (P<0.001). Female gender (aOR=1.25, 95% CI 1.10-1.41), nightmares (aOR=4.22, 95% CI 3.45-5.17), sleep talking (aOR= 2.36, 1.73-3.23), sleep maintenance problems (aOR=1.34, 95% CI 1.15-1.56), symptoms of REM sleep behavior disorder (RBD; aOR=1.24, 95% CI 1.09-1.41) and repeated disturbing thoughts (posttraumatic stress disorder (PTSD) symptoms) were associated with high DRF. Age group 55-64 years (aOR=0.69, 95% CI 0.58-0.83) reported less high DRF than younger participants. Unadjusted OR showed associations between depression, anxiety, and DRF; however, in adjusted regression depression (aOR= 0.71, 0.59-0.86) and anxiety (aOR=0.79, 95% CI 0.66-0.94) were negatively associated with high DRF.

CONCLUSION AND RELEVANCE

DRF was higher than pre-pandemic levels across four continents. DRF was associated with gender and parasomnias like nightmares and RBD symptoms, sleep maintenance problems, PTSD symptoms and negatively associated with depression and anxiety. The results implicate that COVID-19 is reflected in our dreams as an expression of the emotional intensity of the pandemic.

Sleep medication and melatonin use among Norwegian nurses - A cross-sectional study

Aim

To estimate the prevalence of sleep medication and melatonin use among nurses and to assess if factors related to work, sleep or mental health, were associated with such use.

Design

A cross‐sectional study.

Methods

A questionnaire survey including 2,798 Norwegian nurses. Associations were estimated using a modified Poisson regression model.

Results

In total, 7.5%, 4.6% and 2.0% of the nurses included in the present study reported prescribed sleep medication, over‐the‐counter sleep medication or melatonin use in the last year, respectively. Short sleep duration, sleep problems and psychological conditions were strongly associated with both prescribed and over‐the‐counter sleep medication use. Nurses who worked more than 60 night shifts in the last year were at increased risk of sleep medication use.

Partner perceptions are associated with objective sensor-measured adherence to oral appliance therapy in obstructive sleep apnea

The aims of the present prospective clinical study were to determine objective, sensor-measured adherence to a mandibular advancement device (MAD) in patients with obstructive sleep apnea (OSA) and to identify partner-specific adherence-related factors. A total of 77 eligible participants with mild, moderate, or severe OSA and who were non-adherent to continuous positive airway pressure (mean age 56.2 years) participated in the study (32.5% women). The mean (range) observation time between MAD delivery and final follow-up was 8.3 (3.4-16.5) months. The mean apnea-hypopnea index (AHI) was 26.6 events/hr at baseline and 12.5 events/hr at the 8-month follow-up (both p < 0.001). The mean sensor-measured adherence at the 8-month follow-up was 60.1% for ≥4 hr/night of appliance use for ≥5 days/week. Average usage was 6.4 hr/night, when worn. The mean reduction in the AHI was significantly greater in the "good adherence" (Δ 17.4) than the "poor adherence" group (Δ11.0; p < 0.05). From the partner's perspective, the appliance had a positive effect on sharing a bedroom in the good- (55%) compared to the poor-adherence group (25%; p < 0.05) and on their relationship (51.7% versus 17.9%, respectively; p < 0.05). Regression analyses identified the partner's snoring and apneas to be the most significant factor predicting good adherence to MAD (odds ratio 4.4, 95% confidence interval 1.4-14.0). In conclusion, social factors, like partner perceptions, were positively associated with adherence, which indicate that partner's attitudes and support may be a resource that can be utilised to improve adherence in oral appliance treatment of OSA.

Evening-types show highest increase of sleep and mental health problems during the COVID-19 pandemic - Multinational study on 19,267 adults

Study Objectives

Individual circadian type is a ubiquitous trait defining sleep, with eveningness often associated with poorer sleep and mental health than morningness. However, it is unknown whether COVID-19 pandemic has differentially affected sleep and mental health depending on the circadian type. Here, the differences in sleep and mental health between circadian types are examined globally before and during the COVID-19 pandemic.

Methods

The sample collected between May and August 2020 across 12 countries/regions consisted of 19 267 adults with information on their circadian type. Statistical analyses were performed by using Complex Sample procedures, stratified by country and weighted by the number of inhabitants in the country/area of interest and by the relative number of responders in that country/area.

Results

Evening-types had poorer mental health, well-being, and quality of life or health than other circadian types during the pandemic. Sleep–wake schedules were delayed especially on working days, and evening-types reported an increase in sleep duration. Sleep problems increased in all circadian types, but especially among evening-types, moderated by financial suffering and confinement. Intermediate-types were less vulnerable to sleep changes, although morningness protected from most sleep problems. These findings were confirmed after adjusting for age, sex, duration of the confinement, or socio-economic status during the pandemic.

Conclusions

These findings indicate an alarming increase in sleep and mental health problems, especially among evening-types as compared to other circadian types during the pandemic.

Stability and Change of the Personality Traits Languidity and Flexibility in a Sample of Nurses: A 7-8 Years Follow-Up Study

The traits languidity (tendency to become tired/sleepy upon losing sleep) and flexibility (ability to sleep and work at odd times) have been implicated in shift work tolerance. However, there is a dearth of knowledge about their temporal stability. The aim of the present study was to explore these traits during a long follow-up (FU) period and identify factors related to potential changes in trait scores over time. In all, 1,652 nurses completed the Circadian Type Inventory-revised (CTI-r), which measures languidity and flexibility, at both 2008/2009 (baseline, BL) and again in 2016 (FU). The latent scores of these two constructs at BL, in addition to age, sex, childcare responsibility, marital status, night work status, and insomnia status, were regressed on the corresponding latent scores at follow-up using a structural equation modeling (SEM) approach. Stability was found for both languidity (rho = 0.59) and flexibility (rho = 0.58). Both composite scores declined significantly from baseline (20.62 and 12.48) to follow-up (19.96 and 11.77). Languidity at baseline was positively associated with languidity at follow-up (β = 0.89, p < 0.009). Undertaking childcare responsibility between baseline and follow-up was inversely related to languidity at follow-up (β = −0.09, p < 0.05). Starting night work was positively related to languidity at follow-up (β = 0.06, p < 0.05). Developing insomnia between baseline and follow-up (β = 0.15, p < 0.05) was positively, whereas remitting from insomnia during the same period was negatively (β = −0.11, p < 0.01) associated with languidity at follow-up. Flexibility at baseline was positively associated with flexibility at follow-up (β = 0.64, p < 0.05). Having childcare responsibility at baseline, but not at follow-up was inversely related to flexibility at follow-up (β = −0.05 p < 0.05). Becoming cohabitant with a partner between baseline and follow-up (β = −0.07, p < 0.05) was negatively associated with flexibility at follow-up. Starting night work between baseline and follow-up (β = 0.17, p < 0.01) and reporting night work at both baseline and follow-up (β = 0.18, p < 0.01) were both positively associated with flexibility at follow-up, whereas stopping working nights was negatively (β = −0.09, p < 0.05), associated with flexibility at follow-up. The personality traits languidity and flexibility show fairly high stability, albeit the mean scores were significantly reduced during the 7–8 years follow-up period. The results suggest that these personality traits are partly modifiable.

Effect of Continuous Positive Airway Pressure on Symptoms and Prevalence of Insomnia in Patients With Obstructive Sleep Apnea: A Longitudinal Study

Objective

Obstructive sleep apnea (OSA) and insomnia are the two most common sleep disorders. Continuous positive airway pressure (CPAP) is considered first-line treatment for OSA. In the present study, we assess the effect of CPAP on symptoms and prevalence of insomnia in patients with OSA. We hypothesized a decrease in insomnia symptoms from CPAP initiation to follow-up, and that this decrease would depend on CPAP adherence.

Materials and methods

The sample included 442 patients diagnosed with OSA [mean age 54.9 years (SD = 12.1), 74.4% males] who started treatment with CPAP at a university hospital. OSA was diagnosed according to standard respiratory polygraphy. Mean apnea-hypopnea index (AHI) was 30.1 (SD = 21.1) at baseline. Insomnia was assessed prior to CPAP treatment (baseline) and at follow-up after a median of 19.9 weeks (range 6–52 weeks) with the Bergen Insomnia Scale (BIS). CPAP adherence was defined as an average use of ≥ 4 h per night, whereas non-adherence was defined as < 4 h per night.

Results

There was a significant decrease in BIS scores from baseline (mean = 18.8, SD = 9.8) to follow-up (mean = 12.9, SD = 9.9), p < 0.001. Cohen’s d(0.65) indicated a moderate effect size. The reduction in BIS scores was depending on CPAP adherence (interaction effect F(1,440) = 12.4, p < 0.001), with larger reduction in the adherent group than in the non-adherent group. The proportion of patients with chronic insomnia was significantly reduced from 51.1% at baseline to 33.0% at follow-up (p < 0.001).

Conclusion

Overall, there was a significant reduction in insomnia symptoms from baseline to follow-up. The improvement was significant in both adherence groups, but the degree of improvement was larger among patients who were adherent to CPAP. Furthermore, there was a significant reduction in the prevalence of chronic insomnia at follow-up compared to baseline. This suggests that CPAP effectively reduces both the presence of insomnia and the severity of insomnia symptoms in some patients with OSA.

Sleep patterns among Norwegian nurses between the first and second wave of the COVID-19 pandemic

Background

Nurses are in the frontline and play an important role in the battle against the COrona VIrus Disease-2019 (COVID-19) pandemic. Sleep problems among health care workers are likely to increase due to the pandemic. However, it is conceivable that negative health outcomes related to the pandemic fluctuate with the infection rate waves of the pandemic. The present study aimed to investigate sleep patterns among Norwegian nurses, after the first wave, during a period with very low rates of COVID-19.

Methods

Data stemmed from the cohort study “SUrvey of Shift work, Sleep and Health (SUSSH)” among Norwegian nurses. A total of 1532 nurses responded one time to a questionnaire between June and September in 2020 including items about demographics and work, information about COVID-19 and quarantine, sleep patterns and changes in sleep patterns due to the pandemic. Descriptive statistics for all relevant variables were calculated and McNemar tests were used to compare categorical variables.

Results

The majority of nurses (84.2%) reported no change in sleep duration after the first wave of the COVID-19 pandemic compared to before, 11.9% reported less sleep, and 3.9% reported more sleep. Similarly, 82.4% of the nurses reported no change in their sleep quality, whereas 16.2% of the nurses reported poorer sleep quality after the first wave of the pandemic compared to before. The majority of nurses reported no change in their sleep schedule due to the pandemic, although 9.6% of the nurses reported to go to bed later and 9.0% woke up earlier than before the pandemic.

Conclusions

Most existing literature exploring sleep among health care workers during the COVID-19 pandemic has been carried out during periods with high infection rates. In this study we aimed to investigate sleep patterns among Norwegian nurses following the first wave, during a period of low COVID-19 rates in Norway. Most of the nurses reported no change in neither sleep duration, sleep quality, bedtime, nor wake-up times compared to before the pandemic. Still, nearly 12% reported shorter sleep duration, and about 16% reported poorer sleep quality indicating that some nurses experienced worsening of their sleep following the pandemic.

Patients want their doctors' help to increase physical activity: a cross sectional study in general practice

BACKGROUND

Inactivity is prevalent in patients presenting in general practice, and the health benefits of increased physical activity (PA) are well known. Few studies have explored whether patients want their general practitioner's (GPs) contribution in facilitating a lifestyle change.

OBJECTIVE

To identify the characteristics of patients who expect help from their doctor in increasing levels of PA.

DESIGN

We collected data via questionnaires for this cross-sectional study from general practices.

SETTING

General practices in Norway, during Spring 2019.

SUBJECTS

A total of 2104 consecutive patients (response rate 75%) participated.

MAIN OUTCOME MEASURES

The questionnaire included questions about self-rated health, level of physical activity, the desire to become more physically active, and questions about the role of the GP in increasing the level of physical activity in their patients. We analysed our data using Pearson chi-square and binary logistic regression.

RESULTS

Female patients were less active, but their motivation to increase activity and their expectations of receiving help from their doctor were similar to males. Younger patients were more motivated for increased activity, and to manage without help from their doctors. Impaired self-rated health (SRH) was associated with inactivity and, at the same time, with the motivation to become more active with help from general practitioners.

CONCLUSION

Most patients in the GPs' office are physically inactive. This study revealed an important message for GPs: in clinical work, emphasise physical activity for health gains, especially for patients with impaired SRH.Key PointsFour out of five patients attending Norwegian general practice are inactiveMore than 85% of these patients want to increase their physical activity levelMore than 50% would like help from their GP to achieve this goal.

Daylight Saving Time preferences in Norway: Do individual chronotype and home address' latitude and longitude matter?

Daylight Saving Time is highly debated and associated with several health risks. Health experts recommend terminating adjusting the clock time, and to keep permanent standard (winter) time year around. The aims of the study were to investigate preferences for keeping or terminating this biannual adjustment of clock times and for permanent standard or summer time, in the general Norwegian population. Furthermore, we aimed to investigate whether such preferences depended on individual chronotype and home address' latitude/longitude. The online survey included 47,194 participants. Chronotype was measured with the Composite Scale of Morningness (morning types, intermediate types, evening types). Results showed that 78.2% preferred to terminate adjusting the clock time. Summer time year around was preferred by 61.5% whereas 29.1% preferred standard time year around, and 9.4% did not have any preference. Preferences for terminating adjustment of clock times and summer time year around were found in all chronotypes and regardless of living south (latitude 58-59°N), north (latitude 69-71°N), west (longitude 5-6°E) or east (longitude 19-31°E). However, a relatively larger proportion of evening chronotypes preferred to terminate adjusting the clock time compared to morning chronotypes, and relatively more people living north or east preferred termination than people living south or west, respectively. Permanent standard time was more strongly preferred by extreme morning types in comparison with the other chronotypes. In conclusion, nearly four out of five participants reported to prefer to terminate adjusting the clock time, in line with recommendations. However, in contrast to advice from health experts, permanent summer time was preferred by twice as many as permanent standard time. Both chronotype and home address' latitude and longitude mattered in regard to such preferences, but only to a small degree.

Ambient bright light treatment improved proxy-rated sleep but not sleep measured by actigraphy in nursing home patients with dementia: a placebo-controlled randomised trial

BACKGROUND

Up to 70% of nursing home patients with dementia suffer from sleep problems. Light is the main zeitgeber to the circadian system and thus has a fundamental impact on sleep-wake behaviour. Low indoor light levels in nursing homes have been reported, and in combination with age-related reductions in light sensitivity, insufficient light exposure is likely to contribute to sleep problems in this population. Increasing daytime light exposure using bright light treatment (BLT) may represent a feasible non-pharmacological treatment for sleep problems in nursing home patients with dementia.

METHODS

The present study reports on sleep outcomes, which are the primary outcomes of the DEM.LIGHT trial (Therapy Light Rooms for Nursing Home Patients with Dementia- Designing Diurnal Conditions for Improved Sleep, Mood and Behavioural Problems), a 24-week cluster-randomised placebo-controlled trial including 8 nursing home units and 69 resident patients. The intervention comprised ambient light of 1000 lx and 6000 K from 10:00 to 15:00, with gradually increasing and decreasing light levels prior to and following this interval, using ceiling mounted light-fixtures and light emitting diode technology. The placebo condition had continuous standard light levels (150-300 lx, ~ 3000 K). Sleep was assessed at baseline and follow-up at week 8, 16, and 24, using the proxy-rated Sleep Disorder Inventory (SDI) and actigraphy (Actiwatch II, Philips Respironics). Mixed linear models were used to evaluate intervention effects, adjusting for relevant covariates such as age, gender, number of drugs, severity of dementia, eye disease, and estimated light exposure.

RESULTS

Sleep as measured by the SDI was significantly improved in the intervention group compared to the control group from baseline to week 16 (B = - 0.06, 95% CI -0.11 - -0.01, p < .05) and from baseline to week 24 (B = - 0.05, 95% CI -0.10 - -0.01, p < .05). There was no effect according to the SDI at week 8 and no significant effects in terms of actigraphically measured sleep.

CONCLUSIONS

Proxy-rated sleep improved among nursing home patients with dementia following 16 and 24 weeks of BLT. These improvements were not corroborated by actigraphy recordings.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03357328 . Registered 29 November 2017 - Retrospectively registered.

The association between high risk of sleep apnea, comorbidities, and risk of COVID-19: a population-based international harmonized study

PURPOSE

Obstructive sleep apnea (OSA) may increase the risk of severe COVID-19; however, the level of potential modulation has not yet been established. The objective of the study was to determine the association between high risk of OSA, comorbidities, and increased risk for COVID-19, hospitalization, and intensive care unit (ICU) treatment.

METHODS

We conducted a cross-sectional population-based web survey in adults in 14 countries/regions. The survey included sociodemographic variables and comorbidities. Participants were asked questions about COVID-19, hospitalization, and ICU treatment. Standardized questionnaire (STOP questionnaire for high risk of OSA) was included. Multivariable logistic regression was conducted adjusting for various factors.

RESULTS

Out of 26,539 respondents, 20,598 (35.4% male) completed the survey. Mean age and BMI of participants were 41.5 ± 16.0 years and 24.0 ± 5.0 kg/m², respectively. The prevalence of physician-diagnosed OSA was 4.1% and high risk of OSA was 9.5%. We found that high risk of OSA (adjusted odds ratio (aOR) 1.72, 95% confidence interval (CI): 1.20, 2.47) and diabetes (aOR 2.07, 95% CI: 1.23, 3.48) were associated with reporting of a COVID-19 diagnosis. High risk for OSA (aOR 2.11, 95% CI: 1.10-4.01), being male (aOR: 2.82, 95% CI: 1.55-5.12), having diabetes (aOR: 3.93, 95% CI: 1.70-9.12), and having depression (aOR: 2.33, 95% CI: 1.15-4.77) were associated with increased risk of hospitalization or ICU treatment.

CONCLUSIONS

Participants at high risk of OSA had increased odds of having COVID-19 and were two times more likely to be hospitalized or treated in ICU.

Circadian typology and implications for adolescent sleep health. Results from a large, cross-sectional, school-based study

STUDY OBJECTIVES

To investigate circadian typology in a large, representative sample of Norwegian adolescents, and its implications for sleep health.

METHODS

The sample included 3920 1^st year high school students aged 16-17 years. Respondents completed a web-based survey, including the short version of the Horne-Ostberg Morningness-Eveningness Questionnaire (rMEQ), the Munich Chronotype Questionnaire (MCTQ) and items on sleep-related behaviors (eg electronic media usage in bed, consumption of caffeinated beverages), sleep beliefs and daytime sleepiness. Data were analyzed using one-way ANOVAs and Chi-squared tests.

RESULTS

In all, 7.8% were categorized as morning, 52.3% as intermediate and 39.9% as evening types, respectively. Evening types had later sleep timing, longer sleep latency, more social jetlag and shorter school day sleep duration than morning types, with intermediate types displaying a sleep pattern between these two extremes. None of the circadian types met the minimum recommended amount of sleep on school nights (ie 8+ hours), and only morning types had a mean sleep duration of 7+ hours (7:19 h, nearly 1 h more than evening types who slept 6:20 h, p < 0.001). Evening types reported more use of electronic media in bed, more consumption of caffeinated beverages and more daytime sleepiness than the other circadian types. They were also less satisfied with their school day sleep duration and perceived it more difficult to change their sleep pattern.

CONCLUSIONS

Results from this study suggest that eveningness represents a sleep health challenge for older adolescents.

Sleep and its Association With Pain and Depression in Nursing Home Patients With Advanced Dementia - a Cross-Sectional Study

Objective: Previous research suggests a positive association between pain, depression and sleep. In this study, we investigate how sleep correlates with varying levels of pain and depression in nursing home (NH) patients with dementia.

Materials and methods: Cross-sectional study (n = 141) with sleep-related data, derived from two multicenter studies conducted in Norway. We included NH patients with dementia according to the Mini-Mental State Examination (MMSE ≤ 20) from the COSMOS trial (n = 46) and the DEP.PAIN.DEM trial (n = 95) whose sleep was objectively measured with actigraphy. In the COSMOS trial, NH patients were included if they were ≥65 years of age and with life expectancy >6 months. In the DEP.PAIN.DEM trial, patients were included if they were ≥60 years and if they had depression according to the Cornell Scale for Depression in Dementia (CSDD ≥ 8). In both studies, pain was assessed with the Mobilization-Observation-Behavior-Intensity-Dementia-2 Pain Scale (MOBID-2), and depression with CSDD. Sleep parameters were total sleep time (TST), sleep efficiency (SE), sleep onset latency (SOL), wake after sleep onset (WASO), early morning awakening (EMA), daytime total sleep time (DTS) and time in bed (TiB). We registered use of sedatives, analgesics, opioids and antidepressants from patient health records and adjusted for these medications in the analyses.

Results: Mean age was 86.2 years and 76.3% were female. Hierarchical regressions showed that pain was associated with higher TST and SE (p < 0.05), less WASO (p < 0.01) and more DTS (p < 0.01). More severe dementia was associated with more WASO (p < 0.05) and TiB (p < 0.01). More severe depression was associated with less TST (p < 0.05), less DTS (p < 0.01) and less TiB (p < 0.01). Use of sedative medications was associated with less TiB (p < 0.05).

Conclusion: When sleep was measured with actigraphy, NH patients with dementia and pain slept more than patients without pain, in terms of higher total sleep time. Furthermore, their sleep efficiency was higher, indicating that the patients had more sleep within the time they spent in bed. Patients with more severe dementia spent more time awake during the time spent in bed. Furthermore, people with more severe depression slept less at daytime and had less total sleep time Controlling for concomitant medication use did not affect the obtained results.

Insomnia disorder: clinical and research challenges for the 21st century

BACKGROUND AND PURPOSE

Insomnia is a common and debilitating disorder that is frequently associated with important consequences for physical health and well-being.

METHODS

An international expert group considered the current state of knowledge based on the most relevant publications in the previous 5 years, discussed the current challenges in the field of insomnia and identified future priorities.

RESULTS

The association of trajectories of insomnia with subsequent quality of life, health and mortality should be investigated in large populations. Prospective health economics studies by separating the costs driven specifically by insomnia and costs attributable to its long-term effects are needed. Ignoring the heterogeneity of insomnia patients leads to inadequate diagnosis and inefficient treatment. Individualized interventions should be promoted. More data are needed on both the impact of sleep on overnight effects, such as emotion regulation, and the potential compensatory effort to counteract diurnal impairments. Another gap is the definition of neurocognitive deficits in insomnia patients compared to normal subjects after chronic sleep loss. There are also a number of key gaps related to insomnia treatment. Expert guidelines indicate cognitive-behavioural therapy for insomnia as first-line treatment. They neglect, however, the reality of major healthcare providers. The role of combined therapy, cognitive-behavioural therapy for insomnia plus pharmacological treatment, should be evaluated more extensively.

CONCLUSION

Whilst insomnia disorder might affect large proportions of the population, there are a number of significant gaps in the epidemiological/clinical/research studies carried out to date. In particular, the identification of different insomnia phenotypes could allow more cost-effective and efficient therapies.

Prevalence of Shift Work Disorder: A Systematic Review and Meta-Analysis

Objectives: No systematic review or meta-analysis concerning the prevalence of shift work disorder (SWD) has been conducted so far. The aim was thus to review prevalence studies of SWD, to calculate an overall prevalence by a random effects meta-analysis approach and investigate correlates of SWD prevalence using a random-effects meta-regression.

Methods: Systematic searches were conducted in ISI Web of Science, PsycNET, PubMed, and Google Scholar using the search terms “shift work disorder” and “shift work sleep disorder.” No restrictions in terms of time frame were used. Included studies had to present original data on the prevalence of SWD in an occupational sample published in English. A total of 349 unique hits were made. In all, 29 studies were finally included from which two authors independently extracted data using predefined data fields. The meta-regression included four predictors (diagnostic criteria, study country, type of workers, and sample size).

Results: The overall prevalence of SWD was 26.5% (95% confidence interval = 21.0–32.8). Cochran Q was 1,845.4 (df = 28, p < 0.001), and the I² was 98.5%, indicating very high heterogeneity across the observed prevalence estimates. Diagnostic criteria (International Classification of Sleep Disorders-2 = 0, International Classification of Sleep Disorders-3 = 1) and sample size were inversely related to SWD prevalence.

Conclusions: The prevalence of SWD was high across the included studies. The between-study disparity was large and was partly explained by diagnostic criteria and sample size. In order to facilitate comparative research on SWD, there is a need for validation and standardization of assessment methodology as well as agreement in terms of sample restrictions.

Changes in work schedule affect the prevalence of shift work disorder among Norwegian nurses - a two year follow-up study

This study aimed to explore how changes in the work schedule would affect the prevalence of Shift Work Disorder (SWD) over time. Two-year follow-up data from 1076 nurses participating in the longitudinal SUrvey of Shift work, Sleep and Health among Norwegian nurses (SUSSH) were included in the study. The questionnaires included measures of work-related factors, i.e., work schedule and numbers of night shifts and quick returns (QRs) worked the last year, as well as questions related to SWD according to the ICSD-3 diagnostic criteria at both baseline and at 2-year follow-up. Data were analyzed with paired samples t-tests, chi-square tests, and logistic regression analyses adjusting for sex and age. Terminating night work was the strongest predictor for recovering from SWD from baseline to follow-up (OR 10.91, 95% CI 6.11-19.46). Additionally, changing the work schedule from day work to night work from baseline to follow-up was the strongest predictor for developing SWD in the same period (OR 4.75, 95% CI 2.39-9.47). Reductions in number of nights (more than 10) and QRs (more than 10) worked the last year were associated with recovering from SWD between baseline and follow-up. Nurses who recovered from SWD had significantly reduced the mean number of night shifts worked the last year from 32.3 at baseline to 20.4 at follow-up (p = .001). Furthermore, an increase of more than 10 nights or more than 10 QRs worked the last year between baseline and follow-up predicted developing SWD. Nurses developing SWD between baseline and follow-up had significantly increased the mean number of nights worked the last year from 25.8 at baseline to 31.0 at follow-up (p =-.043). Changes in night work exposure were the strongest predictors for both recovering from or developing SWD from baseline to follow-up. Reducing exposure to night work and QRs were associated with recovering from SWD and increasing exposure to night work and QRs were associated with developing SWD. The results imply that unfavorable work schedules play a role in the development of sleep problems among nurses. These results may be useful when designing healthy working schedules.

Insomnia - A Heterogenic Disorder Often Comorbid With Psychological and Somatic Disorders and Diseases: A Narrative Review With Focus on Diagnostic and Treatment Challenges

Patients with insomnia complain of problems with sleep onset or sleep maintenance or early morning awakenings, or a combination of these, despite adequate opportunity and circumstances for sleep. In addition, to fulfill the diagnostic criteria for insomnia the complaints need to be associated with negative daytime consequences. For chronic insomnia, the symptoms are required to be present at least 3 days per week for a duration of at least 3 months. Lastly, for insomnia to be defined as a disorder, the sleep complaints and daytime symptoms should not be better explained by another sleep disorder. This criterion represents a diagnostic challenge, since patients suffering from other sleep disorders often complain of insomnia symptoms. For instance, insomnia symptoms are common in e.g., obstructive sleep apnea and circadian rhythm sleep-wake disorders. It may sometimes be difficult to disentangle whether the patient suffers from insomnia disorder or whether the insomnia symptoms are purely due to another sleep disorder. Furthermore, insomnia disorder may be comorbid with other sleep disorders in some patients, e.g., comorbid insomnia and sleep apnea (COMISA). In addition, insomnia disorder is often comorbid with psychological or somatic disorders and diseases. Thus, a thorough assessment is necessary for correct diagnostics. For chronic insomnia disorder, treatment-of-choice is cognitive behavioral therapy, and such treatment is also effective when the insomnia disorder appears comorbid with other diagnoses. Furthermore, studies suggest that insomnia is a heterogenic disorder with many different phenotypes or subtypes. Different insomnia subtypes may respond differently to treatment, but more research on this issue is warranted. Also, the role of comorbidity on treatment outcome is understudied. This review is part of a Research Topic on insomnia launched by Frontiers and focuses on diagnostic and treatment challenges of the disorder. The review aims to stimulate to more research into the bidirectional associations and interactions between insomnia disorder and other sleep, psychological, and somatic disorders/diseases.

Acoustic pharyngometry - A new method to facilitate oral appliance therapy

Background

There is lack of reliable and accurate methods to predict treatment outcomes of oral appliance (OA) treatment. Acoustic pharyngometry (AP) is a non‐invasive technique to evaluate the volume and minimal cross‐sectional area of the upper airway, which may prove useful to locate the optimal position of OAs.

Objective

This retrospective study aimed to evaluate the effect of applying AP to OA treatment of patients with obstructive sleep apnoea (OSA).

Methods

All patients (n = 244) treated with OAs following an AP protocol at two dental clinics between 2013 and 2018 were invited to participate. A total of 129 patients accepted the invitation, and 120 patients (75 men, 45 women) were included in the analyses. Mean baseline age, BMI and apnoea hypopnea index (AHI) were 59.1 ± 0.9 years, 27.8 ± 0.4 and 21.9 ± 1.1, respectively. Mean follow‐up time was 318 ± 24 days.

Results

AHI at follow‐up was 6.4 ± 0.7, resulting in a treatment success rate of 86.7% (≥50% reduction of baseline AHI). The number of failures (<50% reduction of baseline AHI) did not differ significantly among patients with mild, moderate and severe OSA. 87.6% of the patients reported OA usage every night, and 95.5% reported > 5 hours usage per night, when worn.

Conclusion

The AP protocol applied seems to contribute to the excellent effect of OA treatment in this study. Further research on the application of AP in OA treatment is necessary in order to clarify its possible beneficial contribution to improving OA therapy.

Sleep in older adolescents. Results from a large cross-sectional, population-based study

The aim of the present study was to describe sleep patterns in a large and representative sample of Norwegian adolescents. The sample included 4,010 first-year high school students, aged 16-17 years (54% female), who completed a web-based survey on sleep patterns. The process of going to sleep was addressed as a two-step sequence of (a) shuteye latency (interval from bedtime to shuteye time) and (b) sleep onset latency (interval from shuteye time to sleep onset). Results showed that 84.8% of the adolescents failed to obtain the recommended amount of sleep (8+ h) on schooldays, and 49.4% obtained less than 7 h. Mean bedtime on schooldays was 10:33 PM, with rise time 8:19 h later (time in bed). The adolescents reported long school-day shuteye latency (43 min), limiting sleep opportunity to 7:36 h. Sleep onset latency was 32 min and mean school-day sleep duration was only 6:43 h. On free days, 26.3% of the adolescents obtained less than 8 h of sleep, and 11.7% obtained less than 7 h. Mean bedtime was 00:33 AM, time in bed was 10:35 h, shuteye latency was 39 min and sleep onset latency was 24 min. Mean free-day sleep duration was 8:38 h. There were sex differences in several sleep parameters, including shuteye latency. The results indicate that the majority of Norwegian adolescents fail to obtain the recommended amount of sleep (8+ h) on schooldays. Long shuteye latency appears to be a main driver for short school-day sleep duration in adolescents.

Self-reported seasonality is strongly associated with chronotype and weakly associated with latitude

The aim of this study was to investigate the association between self-reported seasonality, i.e., seasonal variations in mood and related behavior, and chronotype, and between self-reported seasonality and home address' latitude. Data were collected from an online questionnaire with 45,338 participants. Seasonality and chronotype were measured with the Global Seasonality Score (GSS) and the Composite Scale of Morningness, respectively. The participants were categorized into extreme morning types, moderate morning types, intermediate types, moderate evening types, and extreme evening types. Furthermore, participants were categorized depending on home address' latitude. Data were analyzed with chi-square tests and logistic regression analyses adjusting for sex, age, marital status, level of education, and children living at home. Results showed that high seasonality (GSS 11+) was found in 20.9%. The prevalence dose-dependency ranged from 12.2% in extreme morning types to 42.6% in extreme evening types (adjusted OR = 4.21, CI = 3.27-5.41). The prevalence was higher in participants living in North-Norway (latitude from 65 to 71⁰N) versus South-Norway (latitude from 58 to 65⁰N) (23.8% versus 20.7%; adjusted OR = 1.18, CI = 1.08-1.28). When comparing the northernmost (69-71⁰N) to the southernmost (58-59⁰N) counties of Norway, the association was stronger (24.9% versus 18.7%; adjusted OR = 1.37, CI = 1.20-1.56). Among the adjusting variables, high seasonality was associated with female sex, younger age, being unmarried, low level of education, and not having children living at home. In conclusion, about one in five Norwegians reported high seasonality. High seasonality was strongly associated with late chronotype (being an evening type) and weakly associated with living in the north (high latitude).

Predictors and correlates of lifetime and persistent non-suicidal self-injury and suicide attempts among adult survivors of childhood sexual abuse

Background: Childhood sexual abuse (CSA) is a well-established risk factor for non-suicidal self-injury (NSSI) and suicide attempts (SA); still few studies have examined predictors of individual differences in NSSI/SA amongst CSA survivors. Objective: To examine predictors of NSSI and SA among adult CSA-survivors. Methods: In a sample of 516, primarily female adult CSA-survivors recruited from support centres for sexual abuse survivors in Norway, we examined the role of abuse/perpetrator characteristics, and the degree/severity of exposure to other types of childhood maltreatment (cumulative childhood maltreatment; CCM), as predictors of lifetime NSSI and SA. In a subsample of 138 individuals responding to follow-up waves two- and four years later, these same distal factors, as well as previous NSSI and proximal factors in the form of symptoms of mental health disorders (posttraumatic stress, anxiety, depression, sleep disturbances, and eating disorders), relational problems, and perceived social support, were examined as predictors of persistent NSSI. Finally, those attempting new SA during the follow-up period were compared to those who did not on these variables. Results: Higher CCM scores and having had an unknown perpetrator positively predicted lifetime NSSI scores. Higher CCM scores, violent abuse, and having had an unknown perpetrator predicted lifetime SA. Higher CCM scores, previous NSSI, having had a known perpetrator, as well as higher depression-, anxiety- and eating disorder scores, positively predicted persistent NSSI during the four-year follow-up period. Compared to those with no new SA, those reporting new SA during the follow-up period had higher CCM, lifetime NSSI, mental health symptoms and relational problem scores, lower perceived social support scores, and were more likely to have done a past SA and to have experienced abuse involving physical violence. Conclusions: A broad range of both distal and proximal factors should be assessed as potential predictors of NSSI and SA among adult CSA-survivors.

Alerting and Circadian Effects of Short-Wavelength vs. Long-Wavelength Narrow-Bandwidth Light during a Simulated Night Shift

Light can be used to facilitate alertness, task performance and circadian adaptation during night work. Novel strategies for illumination of workplaces, using ceiling mounted LED-luminaires, allow the use of a range of different light conditions, altering intensity and spectral composition. This study (ClinicalTrials.gov Identifier NCT03203538) investigated the effects of short-wavelength narrow-bandwidth light (λ_max = 455 nm) compared to long-wavelength narrow-bandwidth light (λ_max = 625 nm), with similar photon density (~2.8 × 10¹⁴ photons/cm²/s) across light conditions, during a simulated night shift (23:00–06:45 h) when conducting cognitive performance tasks. Light conditions were administered by ceiling mounted LED-luminaires. Using a within-subjects repeated measurements study design, a total of 34 healthy young adults (27 females and 7 males; mean age = 21.6 years, SD = 2.0 years) participated. The results revealed significantly reduced sleepiness and improved task performance during the night shift with short-wavelength light compared to long-wavelength light. There was also a larger shift of the melatonin rhythm (phase delay) after working a night shift in short-wavelength light compared to long-wavelength light. Participants’ visual comfort was rated as better in the short-wavelength light than the long-wavelength light. Ceiling mounted LED-luminaires may be feasible to use in real workplaces, as these have the potential to provide light conditions that are favorable for alertness and performance among night workers.

Sleep and circadian problems during the coronavirus disease 2019 (COVID-19) pandemic: the International COVID-19 Sleep Study (ICOSS)

This protocol paper describes the development of an international collaboration to survey several thousand adults from different countries around the world about their sleep during the coronavirus disease 2019 (COVID-19) pandemic. It is based on the development of a harmonised survey with 50 questions (106 different items) on sleep habits and sleep symptoms that permit comparability of information. The harmonised questionnaire may be used in anonymous cross-sectional surveys, and the instruments within the questionnaire may also be used in prospective studies and clinical studies. The aim was to develop a questionnaire to sample a variety of sleep-wake disorders and other symptoms likely to be caused by prolonged social confinement or by having had COVID-19. The questionnaire was designed to be: (a) simple and, (b) free to use, for research purposes, (c) multilingual, and (d) comprehensive. It can be completed in <30 min. By the end of June 2020, the survey questionnaire had been administered in Austria, Canada, China, Finland, France, Germany, Hong Kong, Italy, Japan, Norway, Poland, Sweden, UK and USA. Research questions to be addressed by the pooled data derived from the participating sites focus on describing the nature and rates of various sleep and circadian rhythms symptoms, as well as their psychological and medical correlates, that arise at various points during the COVID-19 pandemic.