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COVID-19 pandemic: health impact of staying at home, social distancing and ‘lockdown’ measures—a systematic review of systematic reviews

Abstract Background To systematically review the evidence published in systematic reviews (SR) on the health impact of staying at home, social distancing and lockdown measures. We followed a systematic review approach, in line with PRISMA guidelines. Methods In October 2020, we searched the databases Cochrane Database of Systematic Reviews, Ovid Medline, Ovid Embase and Web of Science, using a pre-defined search strategy. Results The literature search yielded an initial list of 2172 records. After screening of titles and abstracts, followed by full-text screening, 51 articles were retained and included in the analysis. All of them referred to the first wave of the coronavirus disease 2019 pandemic. The direct health impact that was covered in the greatest number (25) of SR related to mental health, followed by 13 SR on healthcare delivery and 12 on infection control. The predominant areas of indirect health impacts covered by the included studies relate to the economic and social impacts. Only three articles mentioned the negative impact on education. Conclusions The focus of SR so far has been uneven, with mental health receiving the most attention. The impact of measures to contain the spread of the virus can be direct and indirect, having both intended and unintended consequences. Highlights This article provides a snapshot of systematic reviews published by October 2020. Most of the emphasis has been on the mental health impact of policy measures. The impact on health care delivery and infection control was explored in fewer studies. Other policy areas and social determinants of health had hardly been studied in systematic reviews. The impact of policy measures on health can be direct and indirect.


Introduction
In response to the coronavirus disease 2019 (COVID- 19) pandemic, governments worldwide adopted policies that aimed to reduce transmission, culminating in March and April 2020 in many countries in staying at home and physical (or 'social') distancing measures, often referred to as 'lockdown'. While these measures helped to bring down the number of new infections, gaining valuable time for the health sector to shore up its capacity and expertise for dealing with infected patients, it has become clear that the policy response had wideranging impacts on the health and well-being of populations across all sectors of society and affecting all health determinants.
Faced with new waves of infections in autumn 2020 and winter 2020/2021 and the imposition of new lockdowns in many countries, it is important to understand the positive and negative impacts of lockdowns on the health and well-being of populations to inform future policy responses.
A Health Impact Assessment conducted by Public Health Wales April-May 2020 found that there was a scarcity of academic peer-reviewed research literature regarding the impacts of prolonged quarantine periods and social distancing on health and well-being. 14 However, the academic literature on COVID-19 is evolving rapidly and so a renewed assessment of the academic literature was appropriate.
The overarching aim of this study was to systematically review the evidence published in systematic reviews on the health impact of staying at home, social distancing and lockdown measures.

Methods
A systematic review of systematic reviews was conducted following the Prepared Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. 15 Relevant publications were identified by systematically searching the scientific literature, with the search undertaken on 20 October 2020. We searched the scientific databases Cochrane Database of Systematic Reviews, Ovid Medline, Ovid Embase and Web of Science, using a pre-defined search strategy (detailed search strategies are provided in the Supplementary material).
Inclusion and exclusion criteria for study selection were defined a priori, after piloting them on a sample of 70 articles. Articles were included if they were published in English, were systematic reviews and focused on the health impact of staying at home, social distancing and lockdown measures related to the COVID-19 pandemic or other pandemics. There was no limitation set on the date of publication or the country of study implementation.
Articles published in languages other than English, not concerned with humans, not following a systematic review study design, or not concerned with the health impact of measures were excluded.
Identified studies were reviewed independently for eligibility in a two-step process: a first screen was performed on title and abstract, followed by the screening of full texts. Data were extracted using a standardized data extraction spreadsheet. In cases of doubt, studies were discussed within the research group and consensus reached. Because of the heterogeneity of included studies, no meta-analysis could be undertaken, and the results of our systematic review are presented in the form of a narrative synthesis.

Characteristics of included articles
The majority of systematic reviews included focused on the impact of lockdown measures, with only nine articles focussing mostly on the impact of the pandemic.
Concerning the type of lockdown restrictions, the majority of the systematic reviews was focused on isolation, quarantine and social isolation, with many articles discussing multiple restrictive measures.
• Social isolation: a lack of family support and social isolation had a negative psychological impact on nurses who chose to isolate away from their families (Continued)  To assess the psychological effects in both quarantined and isolated persons compared to non-quarantined and non-isolated persons • Isolation and quarantine: individuals experiencing isolation or quarantine were at increased risk for adverse mental health outcomes, particularly after containment duration of 1 week or longer. Effect sizes were summarized for depressive disorders, anxiety disorders and stress-related disorders. Elevated levels of anger were reported most consistently. There is compelling evidence for adverse mental health effects of isolation and quarantine, in particular depression, anxiety, stress-related disorders, and anger 29 Hossain, M. M., et al.
To synthesize the evidence on mental health outcomes of quarantine and isolation for preventing infectious diseases • Isolation and quarantine: it was reported a high burden of mental health problems among patients, informal caregivers and healthcare providers who experienced quarantine or isolation. Prevalent mental health problems among the affected individuals include depression, anxiety, mood disorders, psychological distress, posttraumatic stress disorder, insomnia, fear, stigmatization, low self-esteem, lack of self-control, and other adverse mental health outcomes 30 Imran, N., et al. (2020) To assess the impact of quarantine on mental health of children and adolescents, and proposes measures to improve psychological outcomes of isolation (Continued)   To describe which non-pharmaceutical interventions used different countries and a when they use them. It also explores how Non-pharmaceutical interventions impact the number of cases, the mortality and the capacity of health systems • Telepsychotherapy is a trustworthy alternative to be adopted, which can be used efficaciously to treat common mental-health disorders such as anxiety, depression and post-traumatic distress. As well as in the traditional setting, a higher number of sessions and the proper management of patients' expectations seem to be asso-ciated with better outcomes. 11   • Quarantine, isolation and social distancing: rapid implementation of these public health strategies is the most effective, and indeed necessary, for containing viruses in pandemics, they also have many potentially negative sequelae and lead to a higher level of distress, fear and anxiety, and drive an increase in levels of panic and uncertainty. These measures are implemented very quickly without very much time for preparation. The rapidity of the change can (in itself) cause community alarm and anxiety. • Quarantine: evidence suggests a link between post-traumatic stress disorder (PTSD) and/or depression and quarantine. There is a positive correlation between length of quarantine and symptoms of PTSD. The psychological symptoms were higher among health-care workers relative to others • Social isolation: working from home, physical distancing, job loss and critical illness from the virus could induce long-term psychological effects in many individuals. Social isolation has been linked to a heightened risk of suicide attempts and suicide and several studies address the connection between job loss and a heightened risk of depression, anxiety and increased substance abuse. Social isolation has also been linked to domestic abuse and violence-related behaviours in the home • Other effects: economic and social impact Zupo, R., et al. (2020) To analyze the preliminary effects of the quarantine lifestyle from the standpoint of dietary habits • Lockdown and quarantine: these results identified: i) a rise in consuption of carbohydrates; ii) more numerous snacks; iii) an high intake of fruits, vegetables and protein and iv) a decreased alcohol intake and fresh fish/seafood consumption. Data were scant on the consumption of junk foods.

Mental health
Overall, almost half of the studies explore the impact of lockdown measures on mental health. 16-19,21,22,24-26,28-34,36-38, 40,44,45,48,49,52 While the rapid implementation of quarantine, isolation and social distancing measures seems to be the most effective strategy to contain the spread of the virus, these measures, when implemented at short notice, can produce alarm and anxiety. 49 The studies reported a high burden of mental health problems among several groups of the population who experienced quarantine or isolation: patients, the general population and health workers. Prevalent mental health issues include anxiety, 17,18,21,[29][30][31]33,37,44,49,52 depression, 17,18,29,30,37,44,52 post-traumatic stress disorder (PTSD), stress, 17,19,21,22,25,26,[29][30][31]37,49,52 and stigmatization. In particular among children, older people and health workers the evidence suggests a link between PTSD and quarantine or isolation. 21,25,30,31,37,52 Stigma is linked both to quarantine and isolation 30 and particularly experienced by health workers 21 and children 31,48 ; the two groups experienced stigma due to quarantine even if they had been confirmed to be negative. 31,48 Health care delivery The pandemic and the subsequent lockdown measures had a negative impact on health care delivery, resulting in limitations to available health care services. These restrictions included: the postponement of non-urgent outpatient visits and of non-urgent surgical interventions, the reduction of non-essential services, and restrictions in accessing hospitals for both patients and their caregivers. 1 The included studies find that restrictions of health care services posed enormous challenges to patients and health care providers, and telemedicine has been proposed by several authors as a potential solution to overcoming the barrier in accessing health care services, especially for outpatient care. 3,5-11, 13 Tele-psychotherapy 8,11 has been evaluated in treating common mental-health disorders such as anxiety, depression and PTSD. The use of telemedicine has also been investigated in orthopaedic care. 3,7 The resulting reduction in inpatient and outpatient orthopaedic care and the increase in remote orthopaedic care was associated with high patient satisfaction related to convenience and reduced waiting and travelling times. Evidence suggests that telemedicine in orthopaedic care can be safe and cost-effective, with high patient and clinician satisfaction. 7 The restrictions of rehabilitation services due to lockdown measures increased, especially among older people, the risk of frailty, sarcopenia, dementia, cognitive decline and depression, in particular among those quarantined at home or with restricted mobility. 1 Yet, a systematic review on telerehabilitation identified 53 challenges in the literature (e.g.: on sustainability and privacy) that could affect the development of tele-rehabilitation. 9 Finally, a systematic review on the delivery of urogynaecology care using telemedicine 6 identified the clinical situations that would allow virtual settings and those that should be managed with an in-person visit despite the risks of COVID-19 transmission.

Infection control
The effect of lockdown measures on infection control was investigated in 12 systematic reviews. 23,27,35,36,[41][42][43]46,48,50,51 According to Chandana et al ., 27 quarantine is one 'of the most misunderstood and feared methods of controlling COVID-19, because it may affect both infected and noninfected individuals with psychological, economical and emotional complications such as post-traumatic stress disorder, depression, insomnia, mood swings'. They continue that the lockdown of a city 'was proved to be effective when a study reported 72% drop in the number of infected people'. 27 A systematic review conducted in China 35 emphasises that the lockdown of a city reduced the reproduction number (R0) from 3.77 to a controlled reproduction number (Rc) of 1.88 after lockdown. Other public health measures implemented, apart from citywide lockdowns and, encompassing contact tracing, intensification of screening, quarantine and mask utilisation, may also be contributing to containing the spread of the virus. 35 In fact, some systematic reviews suggest that combinations of different control measures are the most effective way to reduce transmission of the disease, prevent the collapse of health care services and reduce mortality. 41,43 Concerning travel restrictions, a systematic review on COVID-19, SARS and MERS suggested that travel restrictions leading to reduced transmissibility can be highly effective in containing the spread. 42 In line with these results are those retrieved by the Cochrane Systematic Reviews developed by Burns et al ., 23 which found that travel-related control measures during the COVID-19 pandemic may have a positive impact on infectious disease outcomes. In particular, travel restrictions may limit the spread of disease across national borders, while entry and exit symptom screening measures on their own are not likely to be effective. The evidence is scant on the effectiveness of travel-related quarantine 23 and there is very low-certainty evidence on the effect of quarantine of travellers from a country with a declared outbreak on reducing incidence and death. 41 Finally, systematic reviews on the impact of school closures found that they do not seem to be effective 42 and do not contribute to the control of the epidemic. 50

Children, child development and desire for parenthood
Six systematic reviews on children and their development 17,20,28,37,42,50 have been included in our study. The focus on the limited effect of school closures on pandemic control, 42,50 as discussed above, and on adverse effects of school closures on issues including: increased risk of transmission from children to grandparents, harms to child welfare particularly among the most vulnerable pupils, nutritional issues and the loss of teaching/learning and socialization processes. Importantly, children miss out on public policies taking place in schools, such as balanced and free food programs, guidance about personal hygiene, physical activity and citizenship initiatives. 50 Social isolation in children may increase the risk for cardiovascular disease, reduce physical activity and have negative effects on mental health, 20,50 such as an increased likelihood of high rates of depression and anxiety during and after enforced isolation. 37 Quarantine in children is linked to anxiety, stress and depression and can become a risk factor for child growth and development. 17 Isolation and quarantine together are related to an increased risk of requiring mental health services and to higher levels of post-traumatic stress. 37 A systematic review found that during quarantine, despite a reduction in the quality of life, there was an increased desire for parenthood, although it is unknown if these changes are associated with an increase in terms of birth rates. 39

Older people
Despite quarantine and isolation being the most effective strategies for prevention of the secondary transmission of disease, the evidence suggests a greater vulnerability of older people for secondary transmission than other household members. 46 Other negative consequences were also experienced, particularly if quarantine and isolation were in place for an extended period, and the loneliness caused by social isolation has been associated with impaired cognitive function in older adults. 36 Lockdown in older people with a subsequent reduction in social participation and physical activity during home confinement was identified as a serious concern, as they are typically more inactive and more disposed to chronic disease. 18,20 Finally, a systematic review on older people in nursing homes emphasized that older people suffer from social distancing due to isolation and confinement. The evidence on this however was limited because only few studies with a small sample size and using unreliable methods were included in this systematic review. 40

Well-being and quality of life
Only five systematic reviews were retrieved on well-being and quality of life (QOL). 18,19,21,39,44 Importantly, four systematic reviews explored the impact of lockdown measures on health workers in terms of well-being and QOL. 18,19,21,44 According to the evidence summarised in these studies, healthcare professionals who had been quarantined had more severe symptoms of post-traumatic stress than the general population, felt stigmatised, presented more avoidance behaviours, reported huger lost income and were more affected at the psychological level. 21 Quarantine in the general population was linked to a reduction of the mean wellbeing scores, 39 work-related stress, burnout, 19 frustration, fears of infection, boredom, inadequate supplies and inadequate information. 21 Finally, lockdown and social distancing were linked in the general population to a negative psychosocial impact, an increased prevalence of depression, anxiety, sleep, alcohol use disorders and the fear of being infected. People were also worried about their loved ones. 18,19,44

Substance abuse
The four systematic reviews 16,18,28,52 focussed on the correlation of infection control measures and substance abuse found that lockdown was associated with increased alcohol use disorders in the general population, 18 and social isolation and quarantine were identified as potential contributors to the aggravation of substance abuse. 16,52 Violence and abuse A link between lockdown and domestic violence and abuse was identified in four systematic reviews, 16,28,45,52 with three of them 16,28,52 also exploring substance abuse (see previous section).
Social isolation was linked to domestic abuse and violencerelated behaviour in the home. 52 A systematic review identified that some factors increasing women's vulnerabilities to violence were exacerbated during the social distancing and lockdown period. 45 Even quarantine can increase the power and control abusers hold over victims and trigger violence. 16,45 To overcome this issue with regard to children, South Africa's strict lockdown offered protective pathways, including a policy to protect children at risk of abuse. 28

Lifestyle and dietary habits
Among the 51 systematic reviews included in our study, only two 20,53 focussed on lifestyle and dietary habits. Lockdown and quarantine were found to be associated with an increase of carbohydrate consumption, as well as more frequent consumption of snacks, although together with a high consumption of fruits and vegetables, and protein sources. 20,53 Social isolation was found to cause a decrease in physical activity and, for children, a decrease in the time devoted to sports, and an increase in time sleeping and spent in front of screens, potentially increasing overweight and obesity among children. 20,53
Overall, the non-pharmaceutical interventions implemented to contain the virus, such as quarantine, isolation, social distancing and community containment, were noted to have important economic 21,27,28,31,43,48,49,51,52 and social consequences. 27,31,43,44,52 In particular, quarantine was associated with the necessity to work, the fear of loss of income, the lost income itself and a reduction in overall productivity resulting in a decline of economic growth. 21,27 Moreover, some systematic reviews 21,28,31,49 identified other fundamental issues, such as the lack or insecurity of supplies and food, and inadequate information, particularly linked to quarantine.
School closures were associated with a loss in teaching/learning and education, as well as with wider social impact and economic harm on working parents, health workers and other key workers being forced from work to care for children at home. 17,50 Moreover, a systematic review 33 on the prevalence of anxiety in medical students during the pandemic identified concerns on economic impact, academic delay, curricular factors and impact on their daily life.
Travel-related control measures related to quarantine had far-reaching economic, social, legal, ethical and political implications. 23 Some populations, such as in west Africa, 47 had difficulties complying with certain measures, such as travel limitations and the closure of markets and places of worship, as the majority of people work in the informal sector, including trading, other businesses, transport and restoration and these jobs are not subject to social protection.

Discussion
This systematic review set out to systematically review the evidence published in systematic reviews on the health impact of staying at home, social distancing and lockdown measures. A number of important findings emerged.
The first relates to the areas that have been studies so far. We intentionally kept a broad focus on all policy areas that are associated with the social determinants of health. Surprisingly, almost half of the studies (25 of 51) explore the impact of lockdown measures on mental health, with the common finding that these measures put a strain on the mental health of patients, the health workers and the general population. The second most commonly studied area, explored in 14 of the 51 included studies, was concerned with health care delivery. Many of these 14 systematic reviews explore the issue of telemedicine, with only indirect references to the Coronavirus pandemic. The impact of lockdown measures on containing the spread of the virus was explored in 12 studies, with the overall finding that these measures are successful and most promising when used in combination. In general, lockdown measures are enacted to contain the virus, but often discontinued for economic or political rather than purely epidemiological reasons. Other areas of the health impact of lockdown measures have received far less attention so far and warrant further research.
A second key finding of our study highlights that the complex and multifactorial nature of the health impact of lockdown measures, which can be both direct and indirect. While the closure of schools, for example, will have a direct impact on the education, mental and physical health of children, an indirect impact is that parents will have to stay at home to look after young children, preventing them from going to work. While our primary interest was on the impact of lockdown measures, it was sometimes difficult to ascertain whether the impact was due to these measures or the pandemic itself. We found that many studies were struggling with the same challenge. Causal pathways are often blurred, as mental health, for example, can be affected by both, policy measures and the pandemic itself. Policy measures aimed at containing the spread of the virus will have to mindful of direct and indirect impacts and intended and unintended consequences.
A third key finding relates to the strength of evidence gathered by October 2020. Unsurprisingly, the evidence on the topic was still mainly focused on the first wave of the COVID-19 pandemic that occurred in spring 2020 and a renewed search of the literature is needed to capture more up-to-date evidence. We also identified methodological and terminological challenges. With regard to the methods used, some narrative reviews are defined by the authors as systematic reviews and vice versa. Furthermore, in many systematic reviews, conclusions are drawn based on a very limited number of papers with often low quality. In addition, in some systematic reviews, the impact of lockdown measures is mainly described in the introduction and the conclusions, rather than in the results section. There is also a need for more terminological clarity. Some authors misuse the terms 'isolation' and 'quarantine' and confuse 'social isolation' with 'isolation'.

Supplementary data
Supplementary data are available at the Journal of Public Health online.