Coronavirus and self-isolation after being in contact with a positive case in England: 1 April to 10 April 2021

• Data collected from 1 April to 10 April 2021 show that the majority (90%) of respondents who were required to self-isolate after being in contact with someone who has tested positive for the coronavirus (COVID-19) reported being fully adherent to self-isolation requirements throughout their 10-day self-isolation period.

• Of respondents who were not adherent to self-isolation requirements, 78% reported that they left the house for non-permitted reasons.

• Contact with non-household members was a non-adherent behaviour reported by 6% of all respondents; of these, 57% allowed one or more visitors into their homes.

• Almost half (48%) of respondents who had downloaded the NHS Test and Trace app received a notification by the app telling them to self-isolate; of these people, 15% received the app notification at least a day before any other sources.

• Approximately one-third (32%) of respondents reported that self-isolation had a negative effect on their well-being and mental health, and 27% of respondents reported having lost income because of self-isolation.

• The deprivation level of a respondent's home address had no significant impact on their understanding of self-isolation guidance, full adherence to the guidance, and having no contact with non-household members, when comparing respondents in this survey and respondents living in deprived areas who were surveyed between 15 March and 20 March 2021.

• The Test and Trace Contacts Insights Survey was undertaken in response to policy questions on the level of adherence to self-isolation requirements of those who have been notified by the NHS Test and Trace service to self-isolate, having been in contact with someone who had received a positive test result for COVID-19, and other information.

Statistician's comment

“It’s reassuring to see that a high percentage of survey respondents are self-isolating after being in contact with someone who has tested positive for COVID-19.

Although being in contact with someone who has tested positive for COVID-19 doesn’t necessarily mean you will test positive, our data shows that people are aware of the risks of spreading the virus, even if they are asymptomatic.

Adhering to self-isolation rules is key in reducing the transmission of COVID-19, even after vaccination.”

Tim Gibbs, Public Services Analysis Team, Office for National Statistics
Follow the Public Services Analysis team on Twitter: @HughStick

Since December 2020, there has been a legal duty in England to self-isolate for 10 days if you live in the same household as a person who has symptoms of the coronavirus (COVID-19) or if you have received a positive test result. This also applies if you have been in close contact with, but do not live with, a person who has tested positive for COVID-19. Prior to this (from September 2020) the legal duty was to self-isolate for 14 days.

This may also include contact with people in a person's support bubble. The legal duty was introduced to enforce existing rules around self-isolation to prevent the spread of the coronavirus.

The latest data on the self-isolation behaviours of individuals who tested positive for COVID-19 are available in Coronavirus and self-isolation after testing positive in England: 8 March to 13 March 2021.

The data presented in this bulletin were collected from individuals ("contacts") who had been identified as a contact of someone who had tested positive for COVID-19. The data were collected at the point when the contacts had recently reached the end of their self-isolation period.

These data were collected from 1 April to 10 April 2021 during a period of national lockdown, when the legal duty to self-isolate had been in place for more than four months. More information on identifying this group of people, self-isolation, and collecting the data can be found in the Glossary and Measuring the data sections.

The majority (90%) of respondents to the survey reported being fully adherent to self-isolation requirements throughout their whole self-isolation period. 1 in 10 people (10%) reported at least one activity during their self-isolation that was not adherent to self-isolation requirements.

Non-adherence with self-isolation legislation is illegal unless there are exceptional circumstances such as emergency medical reasons. More information on adherence to self-isolation requirements can be found in Measuring the data.

For 4% of all respondents, non-adherent behaviour took place during the first 24 hours after being contacted to self-isolate, while 8% of all respondents reported non-adherence during the period after the first 24 hours until the end of the self-isolation period.

Of those reporting non-adherent behaviour, reasons for leaving the home included going to the shops for groceries, toiletries, medicine, or other items (27%), and for outdoor recreation or exercise (13%).

To understand the risk of the coronavirus (COVID-19) spreading, respondents were asked whether, at any point during the period they were required to be self-isolating, they had contact with non-household members. In the first 24 hours after receiving notification to start self-isolating, the majority (96%) had no contact with non-household members. For the period after the first 24 hours until the end of the isolation period, 91% had no contact with non-household members.

A minority (6%) of respondents had contact with non-household members at some point during the whole isolation period.

Of those who had contact with non-household members at some point during their isolation period, around half (55%) had contact somewhere outdoors and 57% had contact in the form of visitors to their home, excluding people visiting for personal care.

Approximately one-third (30%) of respondents developed symptoms of the coronavirus (COVID-19). Of those who reported developing symptoms, half (49%) already had symptoms prior to being contacted and 44% developed symptoms less than a week after being contacted by Test and Trace or via the app.

The most frequent symptoms reported were headaches and fatigue, which were experienced by 64% and 63% of those who developed symptoms, respectively.

Of all respondents who were fully adherent with self-isolation requirements throughout their whole isolation period, 15% had symptoms before being contacted by Test and Trace, and a further 15% developed symptoms on the same day or after being contacted.

Of respondents who developed symptoms at any point, 93% were fully adherent to the self-isolation requirements throughout their whole isolation period. Similarly, of those who tested positive for COVID-19, 91% were fully adherent to self-isolation requirements throughout their whole isolation period.

Approximately three-quarters (74%) of all respondents have taken a test for COVID-19 since being contacted by NHS Test and Trace. Of those, 30% went on to receive a positive test result for COVID-19. In total, 22% of all respondents went on to test positive for COVID-19.

Respondents were asked about their interpretation of the requirements for self-isolation to determine how well they understood self-isolation requirements. Around 7 in 10 people (71%) fully understood the requirements. The remaining 29% of respondents either misunderstood or were unsure of the requirements. These respondents provided one or more incorrect interpretation, or one or more "don't know" answer. More information on understanding of self-isolation requirements can be found in Measuring the data.

The activity that was most likely to be reported by respondents as allowed during self-isolation was going out for medical reasons other than getting or returning a COVID-19 test, for example, a doctor's appointment (11%) (Figure 1).

Attending routine medical appointments, such as doctor's appointments, is not allowed during self-isolation but there are exceptions for medical emergencies. Those who reported that this activity was allowed may have been referring to this exception, so it is possible that understanding of guidance is higher than reported here.

Almost two in five (38%) of all contacts mistakenly believed they could not go out to get or return a COVID-19 test during self-isolation. Answers to the question asking people if they believed they could go out to get a COVID-19 test during self-isolation were not factored into the measure of understanding, as misunderstanding this rule would not prevent the respondent from correctly following the requirements.

Three-quarters of respondents (75%) agreed that "it was easy for me to self-isolate". Approximately one-third (32%) of respondents reported that self-isolation had a negative effect on their well-being and mental health. However, the average life satisfaction score for all respondents was 7.4 (out of 10)¹, which is significantly higher than the life satisfaction of the general adult population in England, at 6.9² Opinions and Lifestyle Survey (COVID-19 module), England, between (7 April 2021 and 11 April 2021). This difference, though, may be affected by a difference in data collection mode.³

Just over a quarter (27%) of respondents reported a financial impact in the form of lost income because of self-isolation. Of those who had been working prior to self-isolation (either in or outside the home)⁴, one in five people (20%) were not paid during the isolation period. A further 6% received only statutory sick pay (Figure 2).

Notes for: Ease and impact of self-isolation

1. Estimates for "all respondents" are calculated from the Test and Trace Contacts Insights Survey between 1 April and 10 April 2021, and represent those required to self-isolate after being in contact with someone who had tested positive for the coronavirus (COVID-19) who responded to the survey.
   

2. Estimates for the "general population" are calculated from the Opinions and Lifestyle Survey (COVID-19 module), England, between (7 April 2021 and 11 April 2021), and represent the population of England.
   

3. Please note that these two surveys have different data collection methods (data for this survey are collected via telephone interviews and data for the Opinions and Lifestyle Survey are collected via online self-completion questionnaires) and therefore should not be compared directly, but can be considered in reference to each other. Mode effects on personal well-being estimates are discussed in the article Data collection changes due to the pandemic and their impact on estimating personal well-being.
   

4. This includes those who were in full-time or part-time paid work, or self-employed, including being part of the Self-Employed Income Support Scheme (SEISS) when they began self-isolating.
   

Half (50%) of all respondents had downloaded the NHS Test and Trace app. Of those, 48% received a notification by the app telling them to self-isolate.

Of those who received an app notification telling them to self-isolate, 15% received the notification at least one day before they were notified by other sources. In comparison, 51% received an app notification on the same day as being notified by other sources, and 24% received an app notification one or two days afterwards.

The majority (95%) of all respondents who received an app notification did not leave home for any reason in the first 24 hours after being asked to self-isolate.

To understand whether there were any differences in understanding, adherence and behaviour during the self-isolation period of contacts living in deprived areas¹ compared with all contacts, a second pilot Test and Trace Contacts Insights Survey (Deprivation Boost) took place between 15 March and 20 March 2021.²

Table 1 shows the proportion of respondents who fully understood self-isolation requirements, the proportion who fully complied with it, and the proportion who had no contact with non-household members throughout the whole period.

The differences observed across the periods in Table 1 were not statistically significant. On these measures, this means that there is no difference in understanding, adherence and behaviour between contacts living in deprived areas and the contacts population as a whole.

Full datasets and methodology details for the Test and Trace Contacts Insights Survey (Deprivation Boost), 15 to 20 March 2021 can be found at this link.

Notes for: Living in a deprived area

1. Contacts in deprived areas are defined as those living in Index of Multiple Deprivation (IMD) deciles 1 to 3.
   
2. The first pilot Test and Trace Contacts Insights Survey took place between 1 March and 6 March 2021. The results can be found here.

Self-isolation

Self-isolation refers to not leaving your home because you have been informed by NHS Test and Trace that you are a contact of a person who has had a positive test result for the coronavirus (COVID-19). You must stay at home and complete 10 full days of isolation. It is a legal requirement to self-isolate if you have been notified to by the NHS Test and Trace service. Your isolation period includes the date of your last contact with them and the next 10 full days. If you develop symptoms, stay at home and arrange to have a PCR test for COVID-19.

In addition to staying home, if you are self-isolating you should not receive visitors, unless the purpose of the visit is to provide essential care.

For further information please see NHS guidance When to self-isolate and what to do.

Lockdown

On 5 January 2021, the UK government announced a further national lockdown for England. On 22 February 2021, the UK government published a four-step roadmap to ease lockdown restrictions in England.

Survey information

The Test and Trace Contacts Insights Survey was compiled in response to policy questions on the level of adherence with self-isolation requirements, the prevalence of behaviour that poses a risk of transmitting the coronavirus (COVID-19), and the impact of self-isolation on well-being and finances. It was produced, run and analysed in a collaboration between the Department for Health and Social Care (DHSC), Public Health England (PHE) and the Office for National Statistics (ONS).

This survey was specifically designed to obtain information on people who have been identified as a contact of someone who had tested positive for COVID-19 and who are at the end of their 10-day self-isolation period. ONS experts were consulted on questionnaire design.

The survey respondents were randomly selected from a list of adults (aged 18 years or over) who had been notified as being in contact with someone who has tested positive for COVID-19 and were required to begin self-isolation between 21 and 24 March 2021 or between 26 and 29 March 2021. Respondents were contacted by telephone and all answers are self-reported.

The statistics contained in this bulletin are Experimental Statistics.

Estimates for this survey

The data were collected between 1 and 10 April 2021. The sample size was 1,100. The sample was stratified to be representative of the age, sex and regional distribution of the population being sampled.

Percentages in this report are based on weighted counts that are representative of the population of adults (aged 18 years or over) notified as being in contact with someone who has tested positive for COVID-19 between 3 March 2021 and 31 March 2021 and are adjusted to address age, sex and regional bias in responses.

Significance testing and confidence intervals have been used to test for differences. Where a difference is statistically significantly different, we can be more confident that the difference really exists.

Of those potential respondents who were successfully contacted by an interviewer, the response rate was 52.8%. When including cases where contact was attempted but not made, the response rate was 17.1%. As with all surveys, these estimates have an associated margin of error.

Identifying individuals at the end of their self-isolation period

Respondents were randomly sampled through the Contact Tracing and Advice Service (CTAS) database, held by NHS Test and Trace. This list was created by NHS Test and Trace to record information about people who have been in contact with someone who had tested positive for COVID-19. The sample was limited to those who had provided a valid phone number and who had been entered onto the CTAS database at the point of sampling.

Three-quarters (73%) of respondents were interviewed within four days of the end of their self-isolation period, in order to minimise recall bias. The longest time between the end of self-isolation and interview was 10 days.

Understanding self-isolation requirements

Respondents to the survey were asked what activities they believed were allowed during self-isolation (from a list of reasons for leaving the home) and how long they believed someone must self-isolate after testing positive. For the purpose of this analysis, respondents were categorised as having fully understood self-isolation requirements if they:

• did not select any reason for leaving the home not permitted during self-isolation (such as going to work or to the shops)

• reported a number between 10 and 14 days for the required number of days that someone must self-isolate after notification

This range above 10 days was included in order not to discount those who believed it necessary to self-isolate slightly longer than stated in current requirements. Those who reported a number above 14 were counted as having misunderstood the requirements.

Some reasons for leaving the home are permitted in exceptional circumstances (such as medical emergencies). Those who reported that certain activities were allowed may have been referring to these exceptions, so it is possible that understanding of guidance is higher than reported here.

Adherence to self-isolation requirements

Respondents were categorised as having adhered to self-isolation requirements if they:

• did not leave their home during self-isolation, except to get or return a test for coronavirus (COVID-19)

• did not receive any visitors during self-isolation, except for visitors supporting their personal care

Individuals who left their home or had visitors for other reasons may have been adherent with the requirements if they did so because of exceptional circumstances. This means a small number of individuals may be mis-categorised as non-adherent.

Adherence is measured until the end of self-isolation, or until the point of the survey if isolation has lasted beyond 10 days because of continued symptoms.

Contact with non-household members

For the purpose of this analysis, contact with non-household members was defined as either physical contact for any length of time or being within two metres (six feet) of someone for at least a few minutes during a trip out of the house. Having visitors to the home was also counted as contact with non-household members if these visitors were not providing personal care.

The main strengths of the Test and Trace Contacts Insights Survey include:

• timely production of data and statistics that can respond quickly to changing needs, as the questions included are reviewed for each wave

• the sample was stratified to be representative of the age, sex and regional distribution of the population being sampled and percentages are based on weighted counts representative of the population

• quality assurance procedures are undertaken throughout the analysis stages to minimise the risk of error

• confidence intervals have been used to determine whether differences across time periods and groups are statistically significant

The main limitations of the Test and Trace Contacts Insights Survey include:

• because of the limited period in which fieldwork took place, it is difficult to reach a large number of people and therefore the overall sample size for the survey is limited

• the behaviour of respondents during self-isolation is self-reported and may be subject to recall-bias, which influences how accurately respondents are able to recall past events and experiences; most interviews took place within four days of the end of self-isolation to reduce this bias

• the Experimental Statistics presented in this bulletin contain uncertainty; as with all survey data based on a sample, there is an element of uncertainty as they are susceptible to respondent error and bias

• because of the nature of the target population, in which a large proportion of contacts self-isolating are members of the same household, it is possible that the sample could include multiple members of the same household