key: cord-0691290-539rpqit
authors: Lin, Ying Ni; Liu, Zhuo Ran; Li, Shi Qi; Li, Chuan Xiang; Zhang, Liu; Li, Ning; Sun, Xian Wen; Li, Hong Peng; Zhou, Jian Ping; Li, Qing Yun
title: Burden of Sleep Disturbance During COVID-19 Pandemic: A Systematic Review
date: 2021-06-28
journal: Nat Sci Sleep
DOI: 10.2147/nss.s312037
sha: f3049769c1a6f56e2055eec43e50d30f309ab6de
doc_id: 691290
cord_uid: 539rpqit

Coronavirus disease 2019 (COVID-19) pandemic may exert adverse impacts on sleep among populations, which may raise awareness of the burden of sleep disturbance, and the demand of intervention strategies for different populations. We aimed to summarize the current evidence for the impacts of COVID-19 on sleep in patients with COVID-19, healthcare workers (HWs), and the general population. We searched PubMed and Embase for studies on the prevalence of sleep disturbance. Totally, 86 studies were included in the review, including 16 studies for COVID-19 patients, 34 studies for HWs, and 36 studies for the general population. The prevalence of sleep disturbance was 33.3%–84.7%, and 29.5–40% in hospitalized COVID-19 patients and discharged COVID-19 survivors, respectively. Physiologic and psychological traumatic effects of the infection may interact with environmental factors to increase the risk of sleep disturbance in COVID-19 patients. The prevalence of sleep disturbance was 18.4–84.7% in HWs, and the contributors mainly included high workloads and shift work, occupation-related factors, and psychological factors. The prevalence of sleep disturbance was 17.65–81% in the general population. Physiologic and social-psychological factors contributed to sleep disturbance of the general population during COVID-19 pandemic. In summary, the sleep disturbance was highly prevalent during COVID-19 pandemic. Specific health strategies should be implemented to tackle sleep disturbance.

Coronavirus disease 2019 (COVID- 19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 outbreak, declared as a global pandemic by the World Health Organization (WHO) on March 11th 2020, has presented an unprecedented challenge to public health systems and caused global economic crises. The uncertainties and fears towards COVID-19, along with the societal consequences of mass lockdown, may lead to sleep disturbance and psychological burdens on a large number of individuals, including patients with COVID-19, healthcare workers (HWs), and the general public.

Sleep plays an essential role on regulation of psychological and physical processes. 1 Poor sleep and sleep disturbance could interact with psychological and physical disorders to worsen health consequences among populations. Several studies have reported impacts of COVID-19 on sleep in specific populations. [2] [3] [4] Sleep disorders may exert negative impacts on the process, prognosis, and rehabilitation of patients with COVID-19. Sleep disorders also affect the working ability of HWs. COVID-19-associated societal responses including home confinement, school suspension, and social isolation also increase the likelihood of sleep disturbance in the general public. However, risk factors for sleep disturbance and its associated health consequences still need to be addressed. Thus, we summarized the current evidence on the prevalence and associated factors of sleep disturbance in patients with COVID-19, HWs, and the general public. The increasing evidence addresses the necessity of awareness and interventions of sleep disturbance during and after COVID-19 pandemic.

Electronic searches were performed in PubMed and Embase, and were updated on Dec 10th, 2020. The following terms were used for the searches, ie (sleep) OR (sleep disturbance) OR (sleep disorders) OR (sleep problems) OR (insomnia) OR (sleep apnea) OR (sleep breathing disorders) AND (COVID- 19) OR (SARS-CoV2). The reference lists of full articles were also searched for relevant publications. The searches were conducted, and the full-text articles were reviewed and analyzed by 2 independent researchers (Lin YN and Li SQ). In case of disagreement between the two reviewers, a third reviewer (Liu ZR) reviewed the articles and consensus among the three reviewers was reached.

Studies were included if (1) the studies were cross-sectional, longitudinal, prospective, retrospective, or case-series in design; (2) the studies targeted populations including HWs, the general public, and COVID-19 patients; (3) the studies provided data of prevalence and/or risk factors of sleep disturbance; (4) the studies were written in English. Studies were excluded if (1) the full-text were unavailable;

(2) studies were not written in English; (3) they were reviews, meta-analysis, conference abstracts, and protocols.

We initially identified 1430 studies. After removing 498 duplicates, we screened the remaining 932 studies by reviewing the titles and abstracts. Totally 136 studies were assessed for eligibility, and finally 86 studies were included in the review ( Figure 1 ).

Study quality was assessed using the Loney criteria through eight items including study design and sampling 934 method, unbias sampling frame, sample size, appropriate measurement, unbiased measurement, response rate, estimates of prevalence, and description of study subjects. 5 Scores range from 0 to 8 points. A total score of 7-8 is considered as high quality, 4-6 as moderate quality, and 0-3 as low quality. The detailed quality assessment of the studies was shown in Table S1 . Study quality was assessed independently by two researchers (Lin YN and Li SQ). In case of disagreement, a third reviewer (Liu ZR) reassessed the studies and consensus among the three reviewers was reached.

Sleep Disturbance in Patients with COVID-19

The prevalence of sleep disturbance (ranging from 33.3% to 84.7%) in hospitalized COVID-19 patients was reported in 6 studies [6] [7] [8] [9] [10] [11] (Table 1) . A retrospective study reviewed the psychiatric medical records of 329 COVID-19 patients, and showed 25.5% received psychiatric consultations, 33% of whom were diagnosed with sleep disorders (insomnia, early awakening, difficulty falling asleep), and 22.6% and 54.8% were prescribed benzodiazepines and non-benzodiazepine sedative-hypnotics (zolpidem), respectively. 10 In an Italian university hospital, 49.51% of 103 hospitalized COVID-19 patients complained of sleep disturbance without any sex difference. It should be noticed that symptoms of sleep disturbance appeared immediately after the admission, and the frequency increased from 36.36% on the first 2 days to 69.23% after 7-day hospitalization, 9 indicating that sleep disturbance in hospitalized COVID-19 patients cannot be simply explained by acute psychological response to the disease. Sleep disturbance was also found in mild patients even in mobile cabin hospitals, of whom more than two-thirds experienced insomnia on entry, but the overall insomnia levels (based on Insomnia Severity Index, ISI scores) were improved before discharge. 6 Sleep disturbance may be associated with the adverse health consequences of COVID-19 patients. Compared to those without sleep disturbance, COVID-19 patients who suffered from sleep disturbance for at least 2 weeks during hospitalization presented with a slower recovery from lymphopenia, an increase in the deterioration of neutrophil-to-lymphocyte ratio. They also had a higher incidence of hospital-acquired infection, longer hospitalization, and an increased need for ICU care than those without sleep disturbance. 12 The findings indicated the negative impacts of a sustained period of sleep disturbance on the delay in recovery of immune dysfunction in COVID-19 patients.

Sleep disturbance continued to bother 29.5-40% of COVID-19 survivors during the early post-discharge period, as reported in 4 studies [13] [14] [15] (Table 2 ). Up to 29.5% of 370 Chinese survivors complained of sleep disturbance during a median time of 22 days after discharge. 13 A comparable proportion of 734 COVID-19 survivors (30.6%) from Bangali reported insomnia, disturbance in sound sleep, and nightmares, 16 while the prevalence (40%) was higher in an Italian study. 14 A French study showed that 30.8% of COVID-19 survivors still suffered from sleep disturbance even 110 days after being discharged, with no difference between ward-and ICU patients, 15 highlighting the need for a long-term follow-up for sleep and rehabilitation consultants.

Preexisting sleep disturbance might increase the susceptibility of COVID-19. 17 A recent cross-sectional study showed that up to 60% of the patients reported sleep problems and had been taking sleeping pills over the past 12 months, 18 indicating a high rate of preexisting sleep problems in COVID-19 patients and a possible role of poor sleep on the susceptibility of COVID-19. Cruz and colleagues have proposed a hypothesis that dysregulation of circadian rhythm and sleep may be associated with increased risk of SARS-CoV-2 infection and the severity of its clinical manifestations. 17 The preexisting obstructive sleep apnea (OSA) and obesity hypoventilation syndrome are common co-morbid diseases in COVID-19 patients. The prevalence of OSA in COVID-19 patients was reported in 6 studies [19] [20] [21] [22] [23] [24] (Table 3 ). In severe COVID-19 patients, the prevalence of OSA reached 21-28.6%. 20, 21 More recently, Perger and colleague conducted sleep tests in 44 COVID-19 patients, and identified 34% with OSA and 41% with central sleep apnea (CSA). Multivariate analysis revealed that higher BMI and higher obstructive AHI were associated with the need of ventilation support. 22 COVID-19 patients with OSA are 1.58 times more likely to develop critical illness. 23 The CORONADO study, which included 1317 hospitalized diabetic patients with COVID-19, also demonstrated that treated OSA prior to admission was associated with the increased risk of death on day 7 (adjusted OR 2.65). 24 Thus, it is possible that OSA is not simply a co-morbidity, but could be a risk factor for poor outcomes in COVID-19 patients. 25 patients. SARS-CoV-2 could invade to the brain, possibly via the olfactory nerves or retrograde trans-synaptic dissemination from the lung to the medullary cardiorespiratory center. 27, 28 SARS-CoV-2 then rapidly spread to specific brain areas including thalamus and brain stem, which play essential roles in sleep control and respiratory regulation, respectively, and thereby increase the risks of abnormal sleep-wake behaviors and SDB. SARS-CoV-2 is also capable of causing secondary neuronal injury due to aberrant innate immune response, leading to chronic neurological sequelae that adversely affect sleep, emotion regulation, pain sensitivity, and energy. 29, 30 This indicates a possible long-lasting impact of COVID-19 on sleep. Additionally, the binding of SARS-CoV-2 to the ACE2expressing endothelial cells together with hypercoagulation status may contribute to the increased risk of cerebrovascular events, which contribute to sleep disturbance including inversed sleep-wake cycle, sleep-disordered breathing (SDB), and increased paradoxical sleep. 31 Symptoms, Severity of COVID-19, and Medication Except for the neuronal pathology caused by the virus, the physical discomforts including cough, fever, pain, and dyspnea may also destroy sleep. Relief of symptoms help to improve sleep in COVID-19 patients. Jiang and colleagues showed that Pittsburgh Sleep Quality Index (PSQI) scores were associated with subjective perception of the disease severity in COVID-19 patients. 32 Yang and colleagues recently found that scores of PSQI were positively associated with severity of pneumonia, and improvement of PSQI scores were positively related to improvement from COVID-19. 33 To be noted, adverse effects of medication, eg the use of corticosteroids, sedatives, beta-blocker, and nonsteroidal antiinflammatory drugs (NSAID) also create and exacerbate sleep problems in COVID-19 patients. Appropriate timing of medication, also called chronotherapy, should be taken into consideration to better fit patients' circadian rhythms and to minimize the side effects of medication on sleep eg. the use of corticosteroids, sedatives, beta-blocker, and nonsteroidal antiinflammatory drugs (NSAID) also create and exacerbate sleep problems in COVID-19 patients. Appropriate timing of medication, also called chronotherapy, should be taken into consideration to better fit patients' circadian rhythms and to minimize the side effects of medication on sleep. 34

Sleep disturbance could also occur as the result of the psychologically traumatic effects of COVID-19. Two-week psychological intervention was able to improve PSQI scores, indicating a relationship between sleep disturbance and mental health in COVID-19 patients. 33 Studies have demonstrated a high prevalence of mental health disorders in hospitalized and discharged patients with COVID-19 due to the fear of the new fatal virus infection, uncertainty about disease progression, worries about physical disability, loneliness and social isolation. 8, 10, 13 Sleep is usually reciprocally associated with mental health. Sleep disturbance, and mental health disorders like depression, anxiety, and PTSD not only share symptoms, but also form a vicious cycle to deteriorate the prognosis in patients with COVID-19.Post-traumatic stress disorder (PTSD) not only share symptoms, but also form a vicious cycle to deteriorate the prognosis in patients with COVID-19.

Environmental factors including noise, abnormal light exposure, patient care activities, diagnostic and treatment procedures contribute to the ICU-related sleep disturbance. A previous study has indicated an innegligible role of environmental factors on sleep disturbance in hospitalized patients with COVID-19, 12 particularly for those critically ill patients. Sleep disturbance occurs frequently in ICU patients, presenting with decreased sleep efficiency, a shift toward light stages of sleep, increased arousals, and abnormal circadian rhythmicity. 35 Taken together, physiologic and psychological traumatic effects of the infection may interact with environmental factors to increase the risk of sleep disturbance in COVID-19 patients. However, several questions remain to be solved. How does sleep change during the acute infection of COVID-19 and what is the patho-physiological mechanism? What is the relationship between sleep disturbance and occurrence and prognosis of COVID-19? Does sleep interference improve the prognosis of COVID-19? Moreover, yet little is known about long-term impacts of COVID-19 on sleep. A recent meta-analysis demonstrated a decrease in the frequency of insomnia from 41.9% (95% CI, 22.5-50.5) during the acute illness to 12.1% (95% CI, 8.6-16.3) after a follow-up duration varying from 60 days to 12 years in patients admitted to hospital for SARS or MERS. 36 In the case of COVID-19, further studies are warranted to illustrate how long sleep disturbance would last after rehabilitation, and to what extent sleep disturbance could be improved over time.

A total of 34 studies were included, with the subjective sleep quality being assessed by using self-reported questionnaires 4,37-69 ( Table 4 ). The prevalence of poor sleep quality in HWs during COVID-19 pandemic ranged from 18.4% to 84.7% based on scores of PSQI, 4,37-47 which were comparable to that before the pandemic. 70 A longitudinal study showed worsened sleep quality in 116 doctors and 99 nurses after one-month during the early COVID-19 outbreak, with a percentage of HWs with PSQI > 5 increasing from 61.9% to 69.3%. 44 The prevalence of sleep disturbance in HWs was generally higher than that in non-HWs or general population. [53] [54] [55] Insomnia is the most prominent symptom with a prevalence ranging from 23.6% to 68.3% based on ISI scores. [48] [49] [50] [51] [52] [53] [54] [55] 57, [59] [60] [61] [62] Moderate-to-severe insomnia with ISI≥15 presented in 6.78%-15%. 48, [50] [51] [52] 54, 55, 57, 59, 61, 62 Another two studies used AIS at a cut-off value of 6 showed 52.8% of nurses, 65 and 68.3% of physicians 66 suffered from insomnia.

Except for insomnia, symptoms of parasomnias including nightmares, sleepwalking, sleep terrors are more frequently reported in HWs than non-HWs. 43 Notably, Zhuo and colleagues carried out a study to investigate overnight sleep in 26 HW with insomnia using medical ring-shaped pulse oximeters, and showed that the incidence of comorbid moderate to severe sleep apnea in insomnia HW reached 38.5%, indicating a high comorbidity rate of sleep apnea and insomnia attributable to stress.HWs with insomnia using medical ringshaped pulse oximeters, and showed that the incidence of comorbid moderate to severe sleep apnea in insomnia HWs reached 38.5%, indicating a high comorbidity rate of sleep apnea and insomnia attributable to stress. 71 Factors Linked to Sleep Disturbance of HWs High Workloads High daily workloads contribute to poor sleep in HWs. Increased working hours were associated higher risk of sleep disturbance. 53, 58 The intensity of physical activity during daily work was negatively associated with sleep duration, and was positively associated with the feeling of tiredness during the wake-up in the morning. 72 Being a shift worker has been reported to have 3.48 times likelihood to experience insomnia in the battle against COVID-19. 43 Irregular and prolonged work shifts disrupt homeostatic and circadian rhythms and cause disturbance of several hormones, including melatonin and cortisol, leading to insufficient or inadequate sleep. Shift work not only impairs daytime function, and increases the risk of critical errors in HWs at work, 73 but may also make HWs themselves more prone to COVID-19 infection. 74, 75 A recent singlecenter, retrospective study showed that implementation of new night shift schedule, changing from a four-day cycle to only daytime work for doctors with emergency techniques and extensive first aid experience and a six-day cycle in other doctors and nurses, significantly decreased the mortality of critically ill patients with COVID-19. 76 Thus, more reasonable shift working schedules that allow for adequate rest for HWs and at the same time, ensure the continuity of treatments for patients, should be highly recommended during COVID-19 emergency status. 76, 77 Occupation-Related Factors Several occupation-related factors contribute to the increased risk of sleep disturbance in HWs. The frontline HWs who are engaged in direct diagnosis, treatment, and care of COVID-19 patients, 41, 45, 46, [48] [49] [50] [51] [52] 54, 60, 63, 65, 66 were more likely to experience sleep disturbance. Being a nurse is a risk factor for sleep disturbance (OR:1.48 to 3.132), 41,46,62 while being a doctor was 0.44 times less likely to develop insomnia. 49 The results were consistent with a previous study showing lower scores on posttraumatic stress in doctors than in nurse during SARS outbreak. 78 However, being consultants and physicians, who took more responsibility on treating COVID-19 patients, were associated with sleep disturbance. 4, 47 The differences may be due to the fact that nurses are more likely to have more intense workloads, more frequent shift works, and more direct contacts with COVID-19 patients than doctors. 49 Education and working experience are also closely associated with sleep problems in HWs. HWs with lower education level, 49 less work experience, 50, 66 and poorer knowledge of crisis response, 41 and who were lack of sufficient protective equipment 57 had higher probability of experiencing sleep problems.

Psychological factors were associated with sleep disturbance in HWs, including psychological symptoms (ie depression and anxiety), 29 DovePress perceived lack of psychological support, 49 and preexisting psychological diseases or sleep medication. 47, 61, 62 The relationship between sleep disturbance and COVID-19related stress may be bidirectional. On one hand, the stress associated with high risk of the virus infection and high patient mortality, perceived physical isolation, the necessity for constant vigilance regarding infection control procedures, and concern about family members could cause anxiety, and depression, 46 and impair sleep quality. On the other hand, poor sleep may result in daytime fatigue, loss of interest, impairment of the daytime function, and increase the risk of critical errors at work, 73 which in turn, worsens psychological condition in HWs. Moreover, other factors including being female, 62,65 being aged 41-45 yrs, 58 being the only child, 37 having burden of caring for the elderly or children, 45 physical condition and medication history, 45, 47, 48, 61, 62 being unmarried, 58 also contribute to sleep disturbance in HWs.

Taken together, high workloads may interact with COVID-19-related stress to increase the risk of sleep disturbance in HWs. The majority of the included studies were cross-sectional surveys showing the prevalence of sleep disturbance in HWs during the pandemic. Only one longitudinal study reported a slight increase in the prevalence of sleep disturbance. 44 Further studies should be conducted to determine the prevalence of new-onset or worsened sleep disturbance during the pandemic. Additionally, the impacts of sleep disturbance on health being, life quality and working performance in HWs during and after the pandemic also need further investigation.

The prevalence of sleep disturbance in the general population during COVID-19 pandemic was reported in 36 studies, ranging from 17.65% to 81%, [79] [80] [81] [82] [83] [84] [85] [86] 24 .66% to 86%, 87-89-93-95-96 and 30% to 56%, 100-103 based on scores of PSQI, ISI and AIS, respectively (Table 5) , which were generally higher than that before the pandemic. 83, 115 However, the effects of COVID-19-related lockdown on the public sleep quality remain controversial. Data from Italian and Australian studies reported that approximately half of the participants experienced worsened sleep quality during the lockdown. 84, 85, 107, 108 Similarly, a study in China showed more than one-third of the participants had increased impaired sleep quality. 91 Symptoms of sleep disturbance commonly overlapped with those of depression, anxiety and PTSD in the general public. 83 On the contrary, a longitudinal study in the United State showed that 47% had improved sleep with longer sleep duration, and only 29% had worsened sleep from baseline to lockdown. 116 Another multicenter study from 11 countries also showed a reduced prevalence of insomnia after 2-month lockdown. 110 The results may indicate societal resilience to the chronic threat of viral infection and the changes of daily life. The varied proportions of sleep disturbance and its changes among the countries may be, at least partially, explained by the difference in epidemic control policy and the public attitude towards COVID-19 crisis. Interestingly, Kocevska and colleagues found that 20% of pre-pandemic good sleepers experienced worsened sleep, while a quarter of participants with pre-pandemic clinical insomnia experienced an amelioration of insomnia during COVID-19 pandemic.-117 They argued that the effects of lockdown on sleep quality is not uniform, and emphasized the individual difference in response to COVID-19 crisis.

The circadian rhythm may be altered due to reduced exposure to sunlight, reduced physical activity and changes in working schedule during COVID-19 lockdown. However, the impacts of circadian rhythm alteration on sleep and other health consequences are controversial. On one hand, reduced social jetlag (driven by delayed mid-sleep on weekdays), reduced social sleep restriction (driven by increased sleep duration on weekdays) and decreased sleep debt may harmonize sleep schedules throughout the week, and thereby may limit the decline in sleep quality during the lockdown. 118, 119 On the other hand, later chronotype, manifested as delayed mid-sleep on weekdays, may be associated with increased risk of mood symptoms including depression, 120 which in turn, may worsen sleep quality.

The impacts of age on sleep during COVID-19 pandemic seem controversial. Two studies revealed that people aged more than 30 yrs are more likely to develop sleep disturbance during COVID-19 pandemic, 88,106 consistent with previous studies showing that the prevalence increased with age. 121, 122 The age-related deterioration in sleep may be attributable to not only the effects of aging on circadian pacemaker and sleep structure but also the increased working and social stress that older people 18 Consistently, three cross-sectional studies reported an increase of sleep problems in college students from baseline to lockdown. [123] [124] [125] It could be explained by the increased sleep vulnerability to stress caused by dramatic changes in their daily life and studies due to home confinement, school suspension, and reduced outdoor activity during the COVID-19 lockdown. Therefore, it could be speculated that the effects of age on sleep during COVID-19 pandemic are complicated and inconclusive, and could be interfered by other social-psychological factors. Sex difference has been reported in the prevalence of sleep problems. Females seemed to be more prone to have sleep problems than males when facing COVID-19 crisis. 79, 83, 91, 92, 98, 100, 105, 106 However, a longitudinal study showed that although females generally scored higher in PSQI and ISI scores within the 4-week home confinement period, they reported a reduction in insomnia and other accompanied psychological symptoms, while males had an increase in PSQI and ISI scores, indicating a narrowed sex gap in sleep quality after a prolonged lockdown. 99 Perceived COVID-19-related stress is another major contributor for sleep disturbance, possibly through a change in emotional state (eg, stress, depression and anxiety). 82, 86, 89, 91, 101, 107 Firstly, people who had direct or potential exposure to COVID-19 84,86,93 may be afraid of being infected and worry about being isolated and quarantined, all of which may exacerbate psychological distress and the accompanied symptoms of sleep disturbance. Secondly, post-traumatic stress due to the high mortality of COVID-19 and the unexpected death of someone close, 83 along with the loneliness due to social distancing or quarantine 90, 98 increased psychological burden, making people prone to PTSD and sleep disturbance. Thirdly, negative attitude towards COVID-19, such as worries about COVID-19, perceived high death risk, perceived difficulty in treatment of COVID-19, being negative about COVID-19 control and emotion-focused coping style, may provoke cognitive arousal and disturb poor sleep quality. 79, 81, 87, 97, 101, 104, 106 Fourthly, the more negative impacts do COVID-19 have on livelihood, the more likely do people develop sleep disturbance. 81, 83, 89, 98, [104] [105] [106] Additionally, geographical factors (eg, living in epicenters or in urban areas), 83,88,90,102 education experience, 89, 97, 98, 100 marital status, 90 a history of chronic diseases or mental illnesses, 57, 79, 90, 92, 97, 98, 102 and changes in daily life 84, 91, 100, 101, 105, 106 were also associated with sleep disturbance during COVID-19 pandemic.

Taken together, sleep disturbance in the general public, which is greatly influenced by social-psychological factors, could be compromised by reduced social jetlag and social sleep restriction during the pandemic. However, sleep disturbance-associated health consequences in the general public still need further investigation.

There were several limitations in the review. Firstly, the majority of the included studies were cross-sectional design. More longitudinal studies are encouraged to determine the temporal changes of sleep disturbance during and after the pandemic. Secondly, the adoption of online surveys in most of the included studies limits the diagnosis of patterns of sleep disturbance and accurate assessment of disease severity. Thirdly, most of the included studies were descriptive. There is a lack of research to address the efficacy of targeted interventions including relaxation techniques, behavioral interventions, sleep medications by population on sleep disturbance and its associated health consequences. Fourthly, inclusion of studies in English only in the review may cause language bias.

In summary, COVID-19 exerts adverse impacts on sleep and brings great burden among various groups of populations. Sleep disturbance, mental illnesses, and physiologic illnesses form a vicious cycle to worsen the prognosis in COVID-19 patients. High workforce, shift work and COVID-19-related stress could increase the risk of sleep disturbance of HWs. For the general public, sleep quality seems more sensitive to social-psychological factors. Therefore, specific health strategies by population should be implemented to tackle sleep disturbance.

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Insomnia and psychological reactions during the COVID-19 outbreak in China

Effects of Covid-19 lockdown on mental health and sleep disturbances in Italy

Prevalence and correlation of anxiety, insomnia and somatic symptoms in a Chinese population during the COVID-19 epidemic

Public mental health under the longterm influence of COVID-19 in China: geographical and temporal distribution

Mental wellbeing (Depression, Loneliness, Insomnia, Daily Life Fatigue) during COVID-19 related home-confinement-A Study from Poland

Mental health during the COVID-19 pandemic: effects of stay-at-home policies, social distancing behavior, and social resources

Insomnia during COVID-19 pandemic and lockdown: prevalence, severity, and associated risk factors in French population

COVID-19 pandemic and lockdown measures impact on mental health among the general population in Italy. Front Psychiatry

Gender-related time course of sleep disturbances and psychological symptoms during the COVID-19 lockdown: a longitudinal study on the Italian population

Psychological health, sleep quality, and coping styles to stress facing the COVID-19 in Wuhan

Insomnia during the COVID-19 pandemic in a Greek population

Sleep quality and mental health in the context of COVID-19 pandemic and lockdown in Morocco

Intolerance of uncertainty and loneliness in older adults during the COVID-19 Pandemic. Front Psychiatry

COVID-19-related factors associated with sleep disturbance and suicidal thoughts among the Taiwanese public: a Facebook Survey

Poor sleep associated with overuse of media during the COVID-19 lockdown

Identifying the associated risk factors of sleep disturbance during the COVID-19 lockdown in Bangladesh: a web-based survey

Depression, anxiety and stress during COVID-19: associations with changes in physical activity, sleep, tobacco and alcohol use in Australian adults

Determinants of the lifestyle changes during COVID-19 pandemic in the residents of Northern Italy

COVID-19 and mental health in Brazil: psychiatric symptoms in the general population

Stay-at-home circumstances do not produce sleep disorders: an international survey during the COVID-19 pandemic

Determining depression and related factors in a society affected by COVID-19 pandemic

Psychological impact of COVID-19 pandemic on general population in West Bengal: a crosssectional study

Sleep disturbances, fear, and generalized anxiety during the COVID-19 shut down phase in Germany: relation to infection rates, deaths, and German stock index DAX

Study of knowledge, attitude, anxiety & perceived mental healthcare need in Indian population during COVID-19 pandemic

The prevalence of insomnia in the general population in China: a meta-analysis

Sleep health early in the coronavirus disease 2019 (COVID-19) outbreak in the United States: integrating longitudinal, cross-sectional, and retrospective recall data

Sleep quality during the COVID-19 pandemic: not one size fits all

Effects of the COVID-19 lockdown on human sleep and rest-activity rhythms

Effects of lockdown on human sleep and chronotype during the COVID-19 pandemic

The relationship between chronotype and depressive symptoms: a meta-analysis

Association of sleepwake habits in older people with changes in output of circadian pacemaker

Sex differences in deterioration of sleep properties associated with aging: a 12-year longitudinal cohort study

Impact of COVID-19 lockdown on sleep quality in university students and administration staff

Sleep pattern changes in nursing students during the COVID-19 lockdown

University students' mental health amidst the COVID-19 quarantine in Greece

This work was funded by the National Natural Science 

The authors declare no conflict of interest.