Test, Trace and Isolate: Behavioural aspects

The goal of a test, trace and isolate (TTI) system for COVID-19 is to monitor infected individuals and their contacts to reduce the spread of the virus. More information is available in the POST rapid response on test, trace and isolate programmes for COVID-19 . The success of a TTI system depends on people’s understanding of their role in the process and their capacity and willingness to participate. This includes how well people understand public health advice on when to request a test or when and how to self-isolate, how they adhere to guidelines, and their willingness to share the details of their contacts and use the NHS contact tracing app.

What evidence has been discussed so far by SAGE?

Since the beginning of the pandemic, several expert groups prepared documents for the Scientific Advisory Group for Emergencies (SAGE); providing insights from behavioural sciences and detailing key behavioural and social interventions in response to COVID-19. As highlighted in a background paper published in April (but not considered at any SAGE meeting) prepared by the Scientific Pandemic Influenza Group on Behaviours (SPI-B), four factors are likely to promote high adherence to public health advice in the context of COVID-19:

1. High perception of risk of COVID-19 to self and others.
2. High perceived efficacy of the advice for reducing infections and deaths.
3. People’s confidence in their ability to follow specific advice.
4. People’s perception of tolerable costs to self and others of following public health advice.

What is the best approach for contact tracing?

On 26 April, the New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG) asked SPI-B to comment on the behavioural aspects of different approaches to app-based contact tracing. A symptom-based approach (based on people reporting COVID-19 symptoms, such as high temperature and cough) was compared with a test-based approach (based on people testing positive for SARS-CoV-2).

The document concluded that symptom-based contact tracing is likely to reduce adherence to advice for contacts to self-isolate in comparison with test-based approaches. This is due to an expected high number of false positives (people with symptoms but not infected with SARS-CoV-2) and the perception that an alert is less likely to represent a genuine risk of COVID-19 exposure. Unknown factors highlighted by SPI-B included the magnitude of these effects, whether the reduction in adherence is offset by the benefits gained by contacting people earlier (rather than waiting for a test result), and how an app-based tracing system may undermine engagement with other methods of contact tracing.

What are the behavioural challenges of test, trace and isolate?

A paper on the behavioural issues related to test, trace, track and isolate was prepared by SPI-B on 6 May and discussed at the SAGE meeting on 7 May. The group outlined that engagement with symptom reporting and contact tracing will likely be reduced by four factors:

1. Uncertainty about whether to report symptoms.
2. Low perceived risk of SARS-CoV-2 infection in self and contacts.
3. Concern about consequences of triggering self-isolation for self/others.
4. Concern about consequences of disclosing contacts.

Transparent and clear messages, or emphasis of the social value of the testing process were identified as possible mitigation strategies.

The document also analysed factors likely to reduce self-isolation following testing and tracing, such as awareness that most periods of self-isolation will not be due to a genuine case of COVID-19, and practical and psychological barriers to self-isolation.

Technological and practical barriers were identified in relation to app-based contact-tracing methods. These included the inability to use the technology (especially for older people), the use of unsuitable phones, and trust barriers, such as concerns about data use.

What are the behavioural challenges of self-isolation?

‘Insights on self-isolation and household isolation’ was published by SPI-B and discussed by SAGE on 9 March. It provided guidance on the initial draft of Public Health England’s ‘Guidance for home isolation of individuals with coronavirus’, urging them to consider the needs of different audiences, such as vulnerable groups or individuals with more severe symptoms. The document also highlighted methods to encourage adherence to guidance, such as emphasising civic duty, and changing social norms. On 14 March SPI-B published a background document on the evidence used to assess behavioural issues around self-isolation and quarantine.

‘COVID-19 housing impacts’ is a paper by SPI-B and the Environmental and Modelling group (EMG), considered by SAGE on 10 September. It summarises the evidence for SARS-CoV-2 transmission within the home, probable risk factors and mitigations. These included co-designed strategies and communications, tailored to the different types of householders, to support mitigation behaviours like handwashing, surface cleaning, ventilation and mask wearing in the home.

‘The impact of financial and other targeted support on rates of self-isolation or quarantine’ is a SPI-B paper discussed by SAGE on 16 September. It describes strategies to promote self-isolation rates, such as providing financial support, non-financial support (including access to food or care for older relatives), information on how, when and why to isolate, and emotional support.

What are the behavioural challenges of test, trace and isolate for people from different cultural backgrounds?

‘Public Health Messaging for Communities from Different Cultural Backgrounds’ is a consensus statement by SPI-B on public health messaging for people from minority ethnic communities published on 22 July and considered by SAGE on 23 July. Considerations relevant for NHS Test and Trace service included the need to hire multilingual contact tracers, and to use clear messages to explain the system and to describe behaviours to follow. SPI-B also highlighted the need to consider concerns about loss of income as a potential barrier to engaging with NHS Test and Trace for more socioeconomically disadvantaged groups.

What are the recommendations of SAGE?

Based on the documents described above, SAGE recognised the importance for the public to understand COVID-19 symptoms to make a TTI system effective (SAGE meeting on 7 May) and the importance of culturally appropriate communication to engage with minority ethnic communities (SAGE meeting on 23 July).

Do people understand of what is being asked of them?

There are limited data available on the level of people’s understanding of the test, trace and isolate systems of the UK. On 28 May a YouGov survey of 3,743 adults in Great Britain reported that the majority of them understood the COVID-19 test and trace systems a fair amount (46%) or very much (9%). However, another YouGov survey of 2,109 adults in Great Britain published on 30 September reported that the majority were fairly unclear (33%) or very unclear (31%) on the rules they should currently follow around COVID-19 (although there was no specific question about the NHS Test and Trace system).

On 3 June Ipsos MORI published a survey of 1,983 people aged 18 and over in Great Britain, conducted on behalf of the Health Foundation, on public attitudes towards a ‘potential smartphone app to track and trace coronavirus outbreaks’. They found that 62% of respondents overall would be likely to download an app, with disparities according to age, socio-economic group and education level. People aged 65 and over; routine and manual workers, people who were unemployed or on state pensions; and people with no formal qualifications were found to be less likely to download an app (55%; 50% and 38%, respectively). In September, another Ipsos MORI survey of 1,060 adults aged 18–75 years in Great Britain reported that the majority would stay at home and self-isolate if they tested positive for SARS-CoV-2 (84%) or were told by NHS Test and Trace they have been in contact with someone who had tested positive (77%). However, a third of respondents felt it was acceptable to break self-isolation rules in order to care for friends or family outside of their household following a positive test (29%) or after being told they have been in close contact with someone who had tested positive for SARS-CoV-2 (34%).

The Tower Hamlets Council in London is currently conducting a survey on NHS Test and Trace to capture views from their residents about the programme. NatCen Social Research, on behalf of the Department of Health and Social Care, conducted interviews about the NHS Test and Trace App based on its pilot in the London Borough of Newham. Data are not yet available.

What are the data on adherence so far?

Data on adherence to test, trace and isolate are gradually emerging. One study based on data collected at the beginning of May on 2,240 participants living in the UK aged 18 years or over identified factors associated with non-adherence with self-isolation as being male, less worried about COVID-19, and perceiving a smaller risk of catching COVID-19.

Another study (not peer-reviewed) based on data collected between 2 March and 5 August on 31,787 people living in the UK, aged 16 years or over, showed low adherence to test, trace and isolate behaviours (including self-isolation, requesting a test, intention to share details of close contacts and isolating). The study also found that non-adherence was associated with men, younger age groups, having a dependent child, lower socio-economic status, greater hardship during the pandemic and working in a key sector.

What are the barriers to adherence?

Multiple factors influence adherence to non-pharmaceutical interventions (which include self-isolation). As highlighted in a commentary on ‘Improving adherence to ‘test, trace and isolate’’, behavioural issues may arise at any stage of the test, trace and isolate process. For instance, identified barriers to reporting of symptoms include lack of knowledge of COVID-19 symptoms, presence of only mild symptoms, or concerns about using the service properly. Adherence to isolation may be affected by financial costs and a lack of a community support system, while reporting of contacts (relevant for non-app based approaches) may be affected by concerns around not causing disruption to other people. Contacts’ adherence to quarantine may be impacted by the anonymity of the system, and by the financial and social impact of quarantine.

What are the barriers for app-based contact tracing?

Experts state that behavioural science has a role in the success of tracing apps. As highlighted by a recent briefing by the British Psychological Society, four behaviours are key for the success of a test and trace app:

1. Download the app.
2. Always carry a functional phone.
3. Identify and report COVID-19 symptoms on app.
4. Respond to app messages to self-isolate.

According to the brief, capability, opportunity and motivation are key to trigger these behaviours. A lack of digital skills, ownership of a suitable device to download the app or concerns about privacy were identified as barriers to triggering these behaviours. These issues are in line with the technological and practical barriers identified by SPI-B (and discussed above). User engagement with apps is further discussed in the latest POST article on Contact tracing apps for COVID-19.

What can be done to overcome the barriers?

On 18 May, the Royal Society published the DELVE report on test, trace, isolate and support. Compliance with guidance was identified among the factors influencing the optimal performance of a test, trace and isolate system. Incentives, including those for app use (such as more rapid testing, and improved access to healthcare advice and support during isolation) were identified as potential solutions to maximise population participation and adherence.

Following the most recent data on adherence discussed above, experts suggested that policy-makers may need to rethink their strategies, in particular with regards to financial support to encourage isolation adherence. One study from 563 adults in Israel, conducted at the end of February (when more than more 5000 Israelis were required to self-isolate at home), found that the reported adherence rate to self-isolation was 94% when compensation for lost wages was assumed, and only 57% when it wasn’t.

A rapid review on how to improve adherence with self-isolation identified a series of strategies for public health providers, including providing a clear rationale for isolation, emphasising social norms, increasing the perceived benefit that isolation will have on public health, and ensuring supplies of food and essentials. Some experts suggest that mass media communications based on empathy, positive mood and social influence may promote adherence to COVID-19 regulations.

Behavioural economics experts suggest that strategies such as providing effective messages, establishing new social norm, ‘defaults’ (automatic behaviours) and incentives can be used as strategies to enhance tracing’s effectiveness and people’s adherence with isolation guidance.

Is there enough research?

The promotion of large-scale changes in human behaviour is a key challenge in epidemic response. Threat perception, social context, science communication, aligning individual and collective interests, leadership, and stress and coping have been identified as crucial social and behavioural factors to consider in the COVID-19 response.

While there is increasing evidence on how to promote hygiene practices, such as the use of hand sanitisers, the evidence on how to promote other behaviours (such as those that are key for TTI programmes) is still scarce and experts argue that behavioural, environmental, social and systems interventions against COVID-19 should not be at the bottom of the research agenda.

Experts convened by the UK Academy of Medical Sciences and the mental health research charity MQ: Transforming Mental Health identified one of the research priorities for the COVID-19 pandemic to be understanding the best methods for promoting successful adherence to behavioural advice while enabling mental well-being and minimising distress.