Compliance with self-isolation and quarantine measures: literature review

Key findings

Adherence to isolation regimes in the UK has varied over the course of the pandemic. At the very beginning, rates of compliance were rather low. The CORSAIR study compared a series of 21 cross-sectional nationally representative online surveys conducted in the UK between 2 March and 5 August 2020 to conclude that while intention to adhere to protective measures was high (around 65%), self-reported adherence was low (18.2% amongst those self-isolating). Non–adherence was associated with men, younger age groups, key-workers, lower socio-economic status, greater hardship during the pandemic, incorrect identification of symptoms, lack of knowledge of the regulations if one develops symptoms, and the presence of a dependent child in the household. Self-reported reasons for leaving the house were having to go to the shops for groceries/medicines, one of the symptoms got better and a medical need other than Covid^[11].

From September 2020 though, Ipsos MORI reported increased levels of willingness to comply with the regulations. The majority of those who took part in their survey of 1,060 UK adults stated that they would stay at home and self-isolate if they tested positive for Covid-19 (84%), or were told by NHS Test and Trace or equivalents across the devolved nations that they had been in contact with someone who had tested positive (77%). Yet, a third of respondents still felt it was acceptable to break self-isolation rules in order to care for friends or family outside of their household^[12].

In the winter of 2020, research from England and Wales showed an increase in the number of self-isolating individuals indicating exercise and contact with people outside their household as reasons for non-adherence to self-isolation guidance, possibly due to the difficulties associated with the length, number, and intensity of restrictions^{[13] [14]}. However, in December, data from the Scottish Government commissioned YouGov polling showed that the vast majority of the sampled population would self-isolate and arrange a test through Test and Protect at the first sign of Covid-19 symptoms and be willing to provide details of those they had been in contact with^[15].

In July 2021, the Scottish Government published interim findings from a study on compliance with self-isolation, which found that 74% of index and contact cases were 'fully compliant'^[16]. Similar percentages were recorded in England and Wales this year. In March, research carried out in England among index cases showed that self-reported full compliance with self-isolation requirements was 82%^[17]. Research on close contacts in Wales reported 78% adherence to self-isolation between November 2020 and January 2021^[18], while a survey administered in England indicated 89% being fully compliant throughout the 10-day self-isolation period in March 2021^[19].

While monitoring rates of compliance, most of these studies have identified differences in adherence relating to a range of factors, including demographic variables. The following sections will present research and data on each of these factors, together with some of the lessons learned from across the globe and recommendations made to promote compliance. Although some factors have also been recorded as particularly relevant during a number of other infectious disease outbreaks, like Ebola^[20] or swine flu^[21], others have only been identified in relation to the current pandemic. These differences will be discussed throughout.

Knowledge about Covid and self-isolation/quarantine requirements

At the beginning of the pandemic, a number of surveys reported limited knowledge of Covid symptoms among respondents. Data from 37 nationally representative surveys in the UK conducted between March 2020 and January 2021 show that only 51% of participants could identify cough, fever and loss of taste and smell as the main symptoms of Covid-19^[22], with women and the highly educated better at naming them, according to one of these surveys administered in June 2020^[23]. Statistics for Scotland were more positive in early November and early December 2020, when more than four in five respondents to a population level survey correctly identified the three main symptoms^[24].

A general confusion about the potential asymptomatic nature of the virus has also been recorded, with many of those who did not comply with self-isolation and quarantine regimes saying they didn't as they believed those measures to be unnecessary in the absence of symptoms^[25]. Some studies highlight how people who have symptoms or test positive for Covid-19 are more likely to isolate than asymptomatic cases or contact cases, again revealing a possible poor understanding of Covid-19 transmission routes. In Norway, self-reported compliance between August and October 2020 was significantly higher among people with symptoms than among those who were asymptomatic^[26]. In the Netherlands, about 95% of the respondents to a survey administered in May and June 2020, indicated that they were willing to self-isolate if they were to receive a positive test result – a percentage that dropped to 84% if a member of their household had tested positive, and 43% in cases where a contact had been diagnosed with Covid-19^[27].

Research carried out in England in February 2021 found that adherence to self-isolation requirements was statistically significantly higher among those who fully understood the requirements (87%) compared with those who misunderstood or were unsure of them (83%)^[28].

All of the above suggests that understanding of the virus and symptoms, and of rules and guidelines, supports better compliance with self-isolation and quarantine.

Lessons learned

Clarity of information about Covid-19, and the benefits of self-isolation and quarantine for society as a whole, is fundamental, if measures are to be perceived as promoting public health rather than simply restricting personal choice and liberties^{[29] [30]}. Focusing on clearer and more effective information campaigns and on the provision of easier access to reliable sources of information could also promote confidence in political and health authorities, and trust in official health advice.

Indeed, the issue of trust is of primary importance and has been indicated as a main predictor of intent to adhere to self-isolation/quarantine regulations. A comparison between 19 European countries suggests that higher levels of trust in political authorities prior to the pandemic resulted in higher rates of compliance^[31]. The only two exceptions were Singapore and Norway. In Singapore, a study on compliance found that high levels of public trust in the government and healthcare services led to non-compliance with preventive measures, due to a widespread belief that individual action was not required to manage the risks^[32].

It has been noted that the association between knowledge about Covid-19 and greater self-reported compliance with preventative measures could be due to the fact that individuals with greater willingness to comply are more likely to seek out information regarding Covid-19 and restrictions^[33]. Yet, the risk that lack of knowledge and misconceptions about the disease and self-isolation and quarantine regimes could hinder public health efforts remains. An incorrect interpretation of official messages could damage the effectiveness of the adopted strategies to tackle Covid-19 even among those who wish to comply^[34].

Furthermore, in the era of social media, it can be challenging for some to identify trustworthy advice among the diverse and unverified sources available, with the proliferation of 'conspiracy theories' and 'fake news' potentially affecting the ways in which the general public is able to engage with the Covid-19 health risk^[35]. Research conducted in Poland in April 2020, for example, shows how 'conspiracy theories' were negatively related to adherence to self-isolation guidelines^[36]. Finally, it has to be kept in mind that while internet services are the main source of information for some, others might lack the financial resources to obtain online services, or lack the ability to navigate online confidently, hence having to depend on fewer resources^[37]. Given the link between trust in information sources, increased knowledge, and compliance, where information is found is of key significance.

Socio-economic status

Intention to adhere to self-isolation and quarantine regimes can be hindered for a number of reasons, with financial constraints and caring responsibilities being two of the most common^[38]. A number of surveys examined in this literature review indicate that rates of compliance are heavily influenced by income support, job protection and support with accommodation. The Liverpool-based pilot evaluation on asymptomatic testing concluded that a major barrier to uptake was the fear of testing positive and not having adequate support to isolate or suffering a loss of income^[39]. In Israel, compliance rates for self-isolation dropped from 94% to less than 57% in February 2020, when monetary compensation for lost wages was removed^[40]. This is in line with what has been observed during other outbreaks such as swine flu or Ebola, where practical issues such as running out of supplies or the financial consequences of being out of work were key to levels of adherence^[41]. Fear of loss of income was the most common reason for non-compliance with self-isolation amongst people in Toronto during the epidemic of SARS in 2003^[42].

Research shows that the possibility of having to self-isolate or quarantine – sometimes more than once – is also related to socio-economic status. People in the lower socio-economic quintiles tend to work in high exposure occupations, live in overcrowded housing, take public transport and be unable to work from home, meaning they are at higher risk of infection^{[43] [44]}.

Those living in six person households are three times more likely than two person households to be infected with Covid-19^[45]. Furthermore, larger households are often multigenerational family groups, including older people who are more at risk of negative outcomes if they contract Covid-19^[46]. A survey administered in South Africa between March and April 2020 found that respondents living in informal dwelling settlements were the least prepared for isolation and quarantine, mostly due to existing societal inequalities and lack of spaces to separate the sick from the rest of the family. Preparedness for isolation regimes was also lower in women, suggesting an intersectional connection between socio-economic status and gender. The authors argue that these data may reflect gender-based disparities in terms of resources between male headed households when compared to female headed households^[47].

A number of studies indicate that individuals from more disadvantaged backgrounds might feel forced to choose between financial and physical health. A cross-sectional survey conducted in March 2020 amongst 2,108 UK citizens found that, while self-reported willingness to self-isolate was consistently high across all income and wealth groups, self-reported ability to self-isolate was three times lower in those with incomes less than £20,000 or savings less than £100^[48].

A comparison between Google Covid-19 mobility reports and comprehensive poverty statistics of 9 African and Latin American countries suggests that the decrease in work mobility is smaller in regions with higher poverty rates, demonstrating that the choice faced is often one between taking the risk to get infected/infect others or falling into extreme poverty^[49]. In Iran two cross-sectional studies conducted in the spring and summer of 2020 produced similar findings. The first showed that people assessing themselves as of lower socio-economic status were less likely to comply with social isolation measures due to a perceived lack of social support^[50]. The second, which was carried out among postgraduate students, identified people's livelihoods and lack of government planning to support low-income groups as major reasons for non-compliance^[51].

Qualitative research conducted in Saudi Arabia also revealed how economic risk was often perceived as more significant than risks to health in certain groups^[52], while researchers from South Africa stressed the importance of alleviating any financial burden resulting from self-isolation in a country where the majority of low-income jobs do not offer paid sick leave^{[53] [54]}. Similar trends have been observed during previous pandemics, when those without access to paid sick leave were more likely to work while unwell than other workers^[55]. Though paid sick leave is common in Scotland, those working within the gig economy and who are self-employed may have limited or no access to this benefit.

Lessons learned

Financial support

Providing financial support and reimbursement of any potential income loss arising from the need to self-isolate or quarantine has been at the core of state interventions in Scotland, across the UK and in a number of countries around the world. There has been a significant effort to align public health responses with people's lived realities, in the awareness that the ability to comply with the public health measures depends on people having the space and resources to do so, without worrying about serious damage to their income or family life. Data from Wales confirm that people who identify sufficient support for self-isolation feel less challenged by the prospect and are more likely to succeed^[56].

Fiscal and monetary policy have been implemented worldwide to reduce structural barriers to self-isolation and quarantine, and minimise the long-term social and economic harm caused by the pandemic. Financial support is sometimes restricted to those who receive government benefits or extended to anyone required to isolate, such as in Singapore, South Korea and Taiwan. It can take the form of a one-off payment (some of the most generous being Australia, the four nations of the UK and South Korea, with an offer of £840, £500 and £270 respectively) or daily payments for each day spent in isolation (for example £25 per day in Taiwan).

The evidence that working outside the house is related to lower compliance also identified a need to improve or enforce guidelines in workplaces and support those who are pressured into returning or continuing to work^[57]. In many cases, employment protection has been offered to those required to self-isolate or parents of children who have to self-isolate. In Scotland a fair work statement to guide employers and employees has been issued in an effort to make sure that workers are not financially penalised for following medical advice^[58].

Finally, the literature suggests that not only it is important to provide people with assurances about their household income, but financial help needs to be provided promptly in order to achieve higher adherence with health regulations^[59]. Data collected in Israel suggest that financial assistance is most likely to be effective and promote compliance if it ensures that those in the poorest households have no drop in weekly income, it is provided rapidly and is easy to obtain^[60]. Other infectious disease outbreaks showed similar patterns. Although financial assistance was available during the Ebola epidemic in Senegal, this was perceived as coming too late, making sick individuals dependent on their families, potentially creating interpersonal conflicts and further affecting their wellbeing^[61].

Practical Support

Together with financial support and employment benefits, a comparative study published in March 2021 identified two other types of successful support packages offered by local governments and community based teams across 20 countries: practical support and comprehensive support services. These include, for example, provision and delivery of food and medicines, care for elderly relatives and alternative accommodation. Practical support has been a key component in the measures implemented in Scotland, where local authorities are offering services such as food/medicine deliveries, dog walking and assistance with self-isolation accommodation. In New York City people with positive results were offered a range of services to help them isolate either at home or in free hotel accommodation, including free deliveries of food and medicines, transport, and dog walking^[62]. A test-to-care model implemented in San Francisco provided those asked to self-isolate with home deliveries of groceries, medication, cleaning supplies and personal protective equipment, increasing participants' trust in the system and resulting in a greater number of contacts being revealed^[63]. In France health teams offered home visits to positive cases and advice on how to self-isolate, while also providing antigen (rapid) tests for household members and extra practical support^[64].

Attempts to improve self-isolation and quarantine rates through non-financial help have addressed mainly the most economically disadvantaged in society, with the aim of resolving any practical needs people might have. In Vermont, government support focused on high risk groups with plans for protection from eviction, state supported housing for homeless people, meal deliveries, and free pop-up testing in high risk communities^[65]. Given the difficulties of isolating for those in large, crowded, and multigenerational households, the provision of accommodation has been deemed particularly important in countries such as Denmark, Norway, South Korea, and Taiwan^[66].

Cultural and language barriers to compliance

Research on rates of compliances in the UK has shown that the ability to self-isolate tends to be lower in certain minority ethnic groups^[67]. These lower rates of compliance could be due to a combination of socio-economic, linguistic and cultural factors.

Ineffective communication from governments and other organisations has been identified as a key factor in misunderstanding self-isolation requirements. A qualitative study conducted in a university in England highlighted how students found that information from both the institution and the government was difficult to read and comprehend, especially for international students for whom English was not their first language^[68]. Research conducted during previous infectious disease outbreaks supports this point. Ethnic and linguistic minorities in Canada, for instance, were found to possess inaccurate information on measures of SARS confinement as a result of both inadequate literacy and a lack of clarity in relevant messaging^[69].

Furthermore, Covid-19 terminology may pose a further barrier. Words translated from English may not retain the exact meaning in another language and result in vague and abstract concepts. Terms such as 'self-isolation' are not always well understood when translated and others like 'Test and Trace' (the English testing and contacting tracing system) could generate confusion, hence affecting contact tracing^[70].

Lessons learned

The importance of providing information accessible in a range of languages and to communities with varying degrees of health literacy plays a vital role in promoting adherence to isolation regimes. The UK's Independent Scientific Pandemic Insights Group on Behaviours (SPI-B) has encouraged the use of multilingual contact tracers and clear messages to reach those in the BAME community^[71].

In the UK, policymakers have also been invited by researchers to tackle communication inequalities by consulting representatives from minority groups, ensuring that the interventions are developed in partnership with the target population, and setting up systems to allow rapid and ongoing feedback to be able to modify communications and strategies where needed^[72]. The role of religious institutions and local leaders could also prove fundamental in addressing the perceived negative consequences of having to miss religious events or disregard the social obligation to visit family or friends if asked to self-isolate^{[73] [74]}. This co-production would serve the purpose of empowering communities and ensuring language does not modify or hide meanings, while also fostering trust in health and political authorities. This is especially important as there may be resistance to health messages when they are perceived as authoritarian, due to a history of colonialism and oppression, and perceptions of institutional racism^[75].

Community support

Individual decision-making is often influenced by interpersonal interactions, by self-perception and perception of others within the community. People tend to be motivated by consideration of others, and feel encouraged to adhere to the regulations if they see others following them. Data collected in the United States in April 2020 showed that the more Americans saw others comply, the more likely they were to follow suit^[76].

Conversely, willingness to comply with rules decreases when others are seen to be violating them^[77]. Evidence from previous infectious disease outbreaks confirms this point. During the swine flu epidemic in Australia, as rumours of people breaking quarantine rules surfaced in school communities, those involved in the outbreak admitted they were more inclined to break quarantine protocols themselves because of that^[78]. This is not only due to what could be called social learning, but also to the fact that individuals tend to be conditional co-operators and reason in terms of reciprocity: seeing others ignoring guidelines may lead individuals to perceive them as having different values, reducing willingness to sacrifice freedoms for each other.

Becoming a target of stigma in the community as an index or contact case has also caused reluctance to get tested and affected adherence to isolation regimes^[79]. SPI-B highlighted how concerns about the consequences of triggering self-isolation for others and having to disclose contacts are likely to affect compliance^[80]. The phenomenon of stigmatisation has been widely observed during other infectious disease outbreaks. Participants in several studies reported rejection from people in their local neighbourhoods, who treated them with fear and suspicion, avoided them or addressed them with critical comments^[81]. This often led the unwell to keep certain symptoms a secret, and fail to seek help or communicate to others that they had been in quarantine^[82]. These examples encourage reflections on the existing risk of aggravating inequalities during the current pandemic.

It has been noted that the role played by social relations in the community is complex, and can influence compliance both positively and negatively. A study conducted in Iran during the Covid-19 outbreak in March 2020 reports that those who received support from their family members were likely to adhere to the regulations in place, whereas those who relied on friends were mostly non-compliant, probably because of the pressure they felt to socialize or group conformity^[83]. Yet, other research shows how those receiving help from outside their household are more likely to adhere to self-isolation and quarantine rules^[84], with data collected in Wales between November 2020 and January 2021 reporting that contact cases who had people supporting them during self-isolation were significantly more likely to be compliant with the regulations^[85].

Lessons learned

Suggestions to target these barriers include looking at ways to link people up with community support mechanisms, for example developing community-based peer education programmes and improving communication infrastructure to reduce the negative social impacts of isolation^[86]. Together with this, improving links with local authorities and community based organisations, and empowering community stakeholders to contribute to the Covid-19 response, could help promote compliance^[87]. Some municipalities in Belgium have set up a website where volunteers who want to help and people who need help can register to find each other^[88]. Finally, emphasising the relatively high prevalence of compliers, rather than accentuating the minority of non‐compliers with self-isolation and quarantine regulations might elicit higher feelings of social connectedness and foster adherence based on positive attitudes towards others^[89]. Communication of the high levels of adherence to self-isolation in Wales has been seen as a strategy that could reinforce this positive prosocial behaviour, especially needed during the vaccine roll-out, when self-isolation regimes are potentially more difficult for people to understand and support^[90].

Sense of civic duty and community belonging

A number of studies report how compliance with rules improves when this is perceived as a contribution to the wellbeing of the community as a whole (although some data suggest improvements relate more to the intention to adhere rather than actual behaviour). Results from an online survey conducted in Scotland in December 2020 indicate that people cared about the impact of their actions not only on those they know personally but also on their wider communities^[91]. Semi-structured interviews with UK citizens repatriated from Wuhan and undergoing supported isolation found that compliance was often motivated by altruism and by a perceived shared identity of 'being in it together' that also improved resilience during quarantine^[92]. Similarly, a cross-sectional online survey undertaken in March 2020 in Australia reported 'I believe it is the right thing to do' as the primary response as to what would motivate respondents to comply with self-isolation measures, suggesting compliance was related to the sense of belonging to a community and willingness to support it^[93].

Lessons learned

Emphasising civic duty and community belonging, and appealing to altruistic motivations have been identified as possible strategies to foster compliance with self-isolation and quarantine advice^[94]. A number of experts have recommended the use of positive messages playing on empathy and a focus on the altruistic nature of engaging in self-isolation and quarantine regimes in mass media communications^[95]. Public health officials have been encouraged to emphasise civic duty in order to increase the perceived benefit that complying will have on public health^[96]. Research suggests that any communication that 'we are all in this together' from political leaders determines a sense of collective self-efficacy and hope, as the leaders are seen as part of the group and as acting for its interest^[97]. The potential of boosting citizens' sense of belonging and obligation to their communities in promoting compliance has been explored in a Japanese study which has recorded an increase of 31% in the likelihood of adopting Covid-19 transmission mitigation behavioural guidelines in people with certain personality traits^[98].

Finally, as increased empathy for those at higher risk predicts increased self-reported positive attitudes to physical distancing, there is also some ground to assume that communication focusing on those at higher risk of severe illness has a potential to promote adherence to wider regulations as well as self-isolation^[99]. Strategies adopted in the Netherlands in this regard are a case in point. The Dutch authorities opted for what they called an "intelligent lockdown" during the first wave, namely a combination of stay at home and social distancing measures, promoted through an appeal to people's sense of morality, responsibility and self-discipline. Not only was reference made to the need to contribute to flatten the curve in order to support intensive care units, but the Dutch Prime Minister asked younger people to be more cautious, not for themselves, but for those they risk infecting, especially older people and those with underlying conditions. A qualitative study investigating this approach concluded that the principles of the intelligent lockdown were mostly in line with factors that were identified as positively influencing compliance^[100].

Risk perception

A number of studies both on the current pandemic and on other disease outbreaks show that the belief that an illness does not pose a serious risk (in terms of transmission and severity of disease outcomes) and the inability to see self-isolation as beneficial are associated with lower adherence^{[101] [102] [103] [104] [105] [106] [107]}. Moreover, risk perception tends to vary according to demographic variables like age and gender, with men and younger people being more permissive and less risk averse than women and older people. A Spanish study from spring 2020 shows that higher levels of optimism in men predicted lower compliance with self-isolation, probably as optimism lowered their risk perception of getting infected^[108]. Similarly, a cross-sectional online survey administered in Canada in May 2020^[109] and a longitudinal non-representative panel study conducted in summer 2020 in Chile^[110] found that men and younger age groups were more likely to engage in Covid-19 related risk behaviours. Research from Jordan is also consistent with this growing body of evidence, demonstrating that women tend to have a higher perception of risk and to adopt health-promoting behaviours^[111].

A correlation between low risk perception and lack of symptoms has also been suggested by a cohort study among Norwegian adults covering the months April to July 2020^[112]. Qualitative research conducted at a higher education institution in England supports this theory: students who experienced Covid-19 symptoms were more likely to comply than students who were self-isolating for other reasons^[113].

Context seems to play a role too, with data from the Office for the National Statistics revealing that students and young people are more compliant at home and in the presence of their loved ones. Indeed, many students felt that the virus was not a threat in their university environment, with some mentioning accounts of people they knew who had the virus but only experienced mild symptoms^[114]. Such a perception is echoed by an Italian study finding that 76.2% of secondary school students who took part in an online survey did not see themselves as a category at risk^[115].

Lessons learned

Communications that highlight the risk of transmission to at risk groups or the exponential nature of transmission might improve compliance and decrease risk-taking behaviours^[116], though the evidence is complex. Policy makers in France have been advised to consider emphasising personal risk in their communications in order to reach those who may be otherwise highly disengaged. The advice was based on two cross-sectional studies conducted at the beginning of the pandemic which found a correlation between a 'conspiracy mentality' and compliance with confinement: according to the researchers, those who believed conspiracies were motivated by self‐interest and, as they perceived an increased personal risk, they were more inclined to adopt government‐driven behaviours with the aim of protecting themselves, rather than wider society^[117].

The positive role played by fear of Covid-19 has also been explored and research shows how those with higher fear scores are more inclined to be compliant with regulations on isolation. The authors of this study explain how fear is indeed a negative emotion characterised by extreme levels of emotive avoidance, yet, it also serves adaptive and protective functions and can, in certain contexts, help to keep individuals safe. Their data suggest that fear could have a functional role in the current pandemic and was a stronger predictor of compliance than moral and political orientation^[118]. On the other hand, research conducted in the USA found that threat and prosocial messages focusing on the societal and communal benefits were equally effective in promoting willingness to self-isolate. The only difference was that the prosocial message was more effective if it produced a strong emotional response, whereas the efficacy of the threat message depended less on this^[119]. These findings are likely to be culturally situated and the adoption of fear messages might have some limitations, where prosocial messages could prove more effective. This would need to be carefully considered in any given context.

It should be noted how the prolonged exposure to a community crisis like the pandemic could result in significant levels of mental distress and increased maladaptive levels of anxiety. A message that is perceived as too threatening could cause people to engage in defensive avoidance, hence to disregard the message altogether. There is a possibility that messages associated with negative emotions might produce instead unnecessary mental health concerns. Together with this, due to the cultural differences in how emotions are expressed, the applicability of these research findings should be carefully evaluated and might not translate cross-culturally. These points will be further explored in the following section.

Mental health

A link between isolation measures and poorer mental health has been observed during previous infectious disease outbreaks^[120]. However, the scale of restrictions people have been asked to abide by during the current pandemic has largely exceeded those experienced in the past and proved even more challenging for individuals' mental wellbeing. Interim findings published in July 2021 by the Scottish Government show how 49% of index and contact cases reported that self-isolation had impacted negatively on their mental health^[121]. Data for England from March 2021 present similar results with 37% of index cases and 32% of contact cases reporting negative mental health impacts^{[122] [123]}. Similarly, respondents to a cross-sectional survey among Albertans were significantly more likely to present with moderate to high stress, significant anxiety, and significant depressive symptoms if they had to isolate^[124]. Concerns about an increase in suicidal thoughts and self-harming during self-isolation, particularly related to the economic consequences of lockdown and isolation regimes, have been raised in another Canadian study from May 2020^[125].

In 2020, the COVIDiSTRESS global survey collected data from respondents in 48 countries and concluded that the prolonged state of emergency and the chronic psychological, social and economic stressors related to it made people less likely to follow restrictions and guidelines^[126]. An association between believing that the lockdown had made one's mental health worse and being less likely to remain at home has been observed^[127], with the CORSAIR study indicating feeling depressed, anxious, lonely or bored as one of the main reasons for breaking with self-isolation^[128].

Qualitative research has identified a range of psychological responses in those required to self-isolate and quarantine, such as confusion, low mood, irritability, sadness, guilt, numbness and insomnia. Participants also often fear being infected or infecting others, and have catastrophic appraisals of any physical symptoms experienced during the quarantine period^[129].

Specific segments of the population seem to be more affected than others. Research conducted amongst Italian citizens aged 60+ showed low compliance in an age group already facing loneliness and isolation before the pandemic, hence struggling with having to stop visits to recreational clubs and the resulting loss of social contacts^[130]. Data from Wales (November 2020 to January 2021) reported significant differences between social groups in relation to self-isolation, with women, young people aged 18-29 and BAME groups more likely to feel lonely or experience mental health difficulties^[131]. A study carried out in India found that some form of psychological distress (worry, helplessness, fear, nervousness and insomnia) was seen most significantly in children and adolescents who had to self-isolate, when compared to their peers who did not need to self-isolate, and this distress was usually associated with loss of father's job or income, or the unavailability of basic goods and services^[132].

Lessons learned

Mitigation measures to promote mental health and compliance have included access to emotional support or clinical interventions delivered remotely where possible^[133]. Recommendations have been made for mapping local resources and sources of support from voluntary and community organisations, in order to provide a valuable asset for contact tracers to signpost self-isolating people to mental wellbeing support^[134].

With people indicating boredom as one of the reasons for non-compliance, some research suggests encouraging people to spend time in arts and crafts, non-productive leisure, or even household chores. UK policy makers have also been advised to consider a partnership with the entertainment industry to provide free access to online games or streaming services^[135].

Other recommendations include the promotion of virtual social interactions, online social reading activities, classes, or exercise routines, and the distribution of inexpensive tablets or laptops to those isolating that do not have one or cannot afford it^[136]. In this respect, social media could play an important role in connecting people isolating with their loved ones or people in similar situations^[137]. It has also been stressed that all these virtual mental health resources should be offered proactively and that individuals in self-isolation or quarantine should not need to reach out themselves for support^[138]. Finally, with people reporting attention and memory difficulties when in self-isolation and quarantine, some have recommended the implementation of psychotherapeutic interventions to enhance resilience^[139].

There is some evidence that long-term psychological effects and implications could disproportionately affect sections of the population also suffering from economic hardship. Given the disproportionate prevalence of mental health difficulties in BAME groups, and the disproportionate impacts on these groups from Covid-19, a need for targeted interventions and campaigns exists. The governments of all four nations have been invited to engage directly with representatives of BAME communities in order to develop culturally appropriate and readily accessible mental health support^[140].

Lessons learned during previous infectious disease outbreaks are also valuable when thinking about ways to support key workers who are more exposed to the disease and to the mental distress that can be caused by catching the virus, fearing becoming ill or having to isolate. During the SARS epidemic in Canada of 2003, a telephone support line was set up for hospital staff in isolation as a means to provide them with a social network^[141]. Other hospitals established intranets or private internet chat rooms for their quarantined workers, while the Center for Addiction and Mental Health (CAMH) created an online forum for doctors and patients to discuss SARS and SARS-related anxiety^[142].

It is worth mentioning that, amongst women, compliance decreased with feelings of loneliness or that one's activities were less worthwhile^[143]. This might negatively affect mental wellbeing in women who are already experiencing extra pressure due to the inequality of housework distribution in the majority of countries, where they are regarded as default caregivers of children and sick family members at home. Supporting individuals to find meaningful social activities to undertake during the pandemic and develop a sense of purpose may promote adherence to self-isolation and quarantine regimes. Such support could be also beneficial to individuals who have lost employment^[144].

Monitoring and enforcement of self-isolation/quarantine rules

With an increase in case numbers and the emergence of new strains of the virus over the course of the pandemic, stricter measures have been implemented to reduce transmission. On 28^th September 2020, a legal duty to self-isolate came into force in England, together with a system of fines for those breaking the rules^[145]. People in Wales and Northern Ireland are also required by law to self-isolate or quarantine^{[146] [147]}. In Scotland, instead, legal obligations only apply to international travellers. However, UK strategies differ from the ones adopted in a number of other European countries where people are asked to provide an official statement on their essential reason to leave home (France and Italy), risk imprisonment if flouting the rules (Germany, Italy, Finland and Norway), or are subject to random checks like in Slovakia. Closing locations such as shops, restaurants, cultural attractions, and so on, and making the violation of restrictions more difficult has been the dominant approach across the UK, with the introduction of managed quarantine hotels for international travellers perhaps representing the most extreme enforcement measure^[148].

Research shows that institution-based isolation (e.g. in a hotel) tends to be more effective than home-based isolation, as it is less reliant on personal adherence to guidelines^[149], with modelling suggesting that it could guarantee a 57% reduction of cases in comparison to 20% reduction achieved through home-based isolation^[150]. Evidence on solutions like regular or random checks, the use of digital surveillance technologies and the implementation of fines is mixed and presents a dimension of cultural variation^[151]. Due to privacy laws and lack of social acceptability or negative public perceptions, most of these strategies have been considered counterproductive in Western countries. Leaders who threaten people with sanctions may also become distrusted, paradoxically failing in eliciting cooperation^[152]. Research conducted in the United States in April 2020 showed that Americans are less likely to comply when they think they must obey authorities out of fear^[153]. Furthermore, qualitative research on the experiences of British nationals who underwent supported isolation after returning to the UK from Wuhan, China in January/February 2020 found that most participants were willing to undergo supported isolation when they felt encouraged rather than enforced^[154].

Lessons learned

Some of the evidence analysed in this review highlighted the importance of intervening to tackle emerging social norms that may not support compliance, for example rumours of others breaking isolation without apparent detrimental effect^[155]. An independent SAGE briefing note states that punishment for blatant and visible violations may also help with maintaining a sense of justice for those adhering to the regulations. Yet, while some research suggests this might have the support of the population^{[156] [157]}, other studies report that it would not have a significant impact. According to a study conducted between March and June 2020 in South Korea, for example, the implementation of stricter sanctions and higher fines had no significant impact on reducing the rate of non-compliance with self-isolation because concerns over the loss of income were more significant^[158].

Enforcement approaches could pose a number of issues, for example discourage testing uptake and honest reporting during contact tracing, or impact more on low-income individuals when it comes to fines. Furthermore, these measures risk focusing on the wrong solutions to low rates of compliance, namely poor knowledge of what is required during self-isolation or lack of adequate financial, practical and social support^[159].