Coronavirus and self-isolation after testing positive in England: 8 March to 13 March 2021

• The data collected between 8 and 13 March 2021 show that the majority (82%) of those required to self-isolate reported fully adhering to the requirements throughout their self-isolation period.

• Non-adherent behaviour was most likely to take place in the period between the onset of symptoms (prompting a test) and receiving a positive coronavirus (COVID-19) test result; adherence once a positive test result was received was significantly higher.

• Of those who had symptoms before being tested, 79% reported adhering to self-isolation requirements between the onset of symptoms and receiving a positive COVID-19 test result.

• In the 24 hours following a positive result, 97% of all those who tested positive reported adhering to the requirements; in the period after the first 24 hours until the end of self-isolation at day 10, 94% reported being adherent.

• The majority (83%) of those who tested positive for COVID-19 reported having no contact with non-household members while they had any symptoms of illness or during the self-isolation period.

• Approximately a third (36%) of those who tested positive reported that self-isolation had a negative effect on their well-being and mental health.

• Approximately 3 in 10 people (28%) reported having lost income because of self-isolation.

• The COVID Test and Trace Cases Insights Survey was compiled in response to policy questions on the level of adherence to the requirement to self-isolate among those who received a positive test result, and the impact this had on their well-being and work situation.

In September 2020, a new legal duty was introduced in England, requiring people to self-isolate for 10 days if they tested positive for the coronavirus (COVID-19). The self-isolation period starts from the day symptoms began or the day of the test if there were no symptoms prior to the test. This legal duty was introduced to enforce previous guidance around self-isolation, in order to prevent the spread of the coronavirus.

The data presented in this bulletin were collected from individuals who had tested positive for COVID-19 and had recently reached the end of their self-isolation period. These data were collected between 8 and 13 March 2021, during a period of national lockdown, when the legal duty to self-isolate had been in place for more than five 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 data collected between 8 and 13 March 2021 show that the majority (82%) of those required to self-isolate reported fully adhering to self-isolation requirements throughout their self-isolation period. A minority of people (17%) reported at least one activity during self-isolation that was not adherent to the requirements, for example leaving the home or having visitors for a reason not permitted under legislation.

Non-adherence with self-isolation requirements 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.

The majority of individuals who did not adhere to the requirements did so by leaving the house for a non-permitted reason (83%). In addition, 27% of those who did not adhere to the requirements had one or more visitors to their home during the self-isolation period, whose visit was not to support their personal care.

Non-adherent behaviour was most likely to take place in the period between the onset of symptoms (which required self-isolation) and receiving a positive COVID-19 test result. See Glossary for more information on symptoms and the self-isolation period.

Of those with symptoms prior to their test, the percentage who fully adhered to requirements between onset of symptoms and a positive test result was 79%. This compares with 97% of all those who tested positive who adhered to the requirements in the 24 hours following a positive result, and 94% in the period after the first 24 hours until the end of self-isolation at day 10.

Of those with symptoms requiring self-isolation, 40% received a positive test result within 24 hours of first having symptoms. Approximately 1 in 5 (18%) received their test result more than 72 hours after their symptoms started.

To understand the risk of the coronavirus (COVID-19) spreading outside of the household, respondents were asked whether they had contact with non-household members at any point when they felt ill or were self-isolating.

When considering the risk of the coronavirus spreading, we consider those with any symptoms of illness before their test, for example, a sore throat. More information on defining contact with non-household members and adherence to requirements can be found in Measuring the data.

This differs from the population who were measured for adherence to self-isolation requirements in the time between onset of symptoms and receiving a positive test, which only includes those with a high temperature, a new continuous cough, or loss of sense of smell or taste (see Glossary).

The majority (83%) of those who tested positive for COVID-19 reported having no contact with non-household members while they had any symptoms of illness or during the self-isolation period. Contact was most likely to take place while out of the house, as 80% of those who had contact with non-household members did so while out of the house. Of those who had contact with non-household members, approximately one third (32%) had visitors to their home. A minority (13%) had contact both while out of the house and in the form of visitors to their home.

Of those who lived with others and were required to self-isolate, 20% reported being able to keep themselves completely separate from other household members. But, the majority (80%) reported being unable to keep themselves completely separate from other household members:

• 38% were not at all able to keep themselves separate
• 17% were able to keep themselves separate some of the time
• 25% were able to keep themselves separate most of the time

The proportion of people who said they were not at all able to keep themselves separate was statistically significantly higher among those who lived with dependent children (45%) compared with those who did not (33%).

Respondents were asked about their interpretation of the requirements for self-isolation, to determine how well they understood these requirements. The majority (70%) of those who tested positive for the coronavirus (COVID-19) fully understood the requirements. Approximately 3 in 10 (30%) either misunderstood or were unsure of the requirements. These people provided one or more incorrect interpretation, one or more "don't know" answer, or a combination of both.

More information on understanding of self-isolation requirements can be found in Measuring the data.

The activity that was most likely to be reported 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). Approximately 1 in 10 people (10%) believed this activity was allowed, and a further 10% were not sure.

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 self-isolation requirements is higher than reported here.

Understanding of requirements varied by age. Those aged 55 years and over were statistically significantly more likely to have misunderstood or to be unsure of the requirements compared with those aged 18 to 34 years.

Of those who adhered to self-isolation requirements, most (84%) agreed that "it was easy for me to self-isolate". Of those who did not adhere to the requirements the percentage who agreed "it was easy" was statistically significantly lower, at 75%.

Approximately a third (36%) of all those who tested positive for the coronavirus (COVID-19) reported that self-isolation had a negative effect on their well-being and mental health. Over half (59%) reported that self-isolation had no effect on their well-being, while 4% said that it had a positive effect.

Of those who had been working prior to self-isolation (either in or outside the home), 55% reported either working as normal (receiving full pay) or receiving full sick pay, while 14% were not paid during the isolation period. Working from home is allowed within the self-isolation requirements.

A further 7% received only statutory sick pay, 7% received reduced sick pay and 15% were not sure how they will be paid.

These estimates relate to usual income and do not take account of other financial support during self-isolation, such as the Test and Trace Support Payment Scheme.

Of all those who tested positive for COVID-19, 9% had applied for a payment through the NHS Test and Trace Support Payment Scheme. Of those who had not applied, 72% said they were aware of the scheme but were not eligible, and 18% said they were not aware of the scheme.

Self-isolation

Self-isolation refers to not leaving your home because you have or might have the coronavirus (COVID-19). It is a legal requirement to self-isolate if you test positive for COVID-19. In addition to staying at home, if you are self-isolating you should not receive visitors unless the purpose of the visit is to provide essential care. Your self-isolation period includes the day your symptoms started (or the day you had the positive test result if you do not have symptoms) and the next 10 full days. If you still have symptoms after 10 days, you must continue self-isolating until they are gone.

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

Symptoms

Symptoms reported by respondents that do not require self-isolation prior to a positive test, if not experienced alongside a high temperature, a new continuous cough, or loss of sense of smell or taste are: shortness of breath or trouble breathing; runny or stuffy nose; muscle or body aches; headaches; sore throat; fatigue; vomiting, diarrhoea or severe stomach pain.

Symptoms requiring self-isolation prior to a positive test result are a high temperature, a new continuous cough, or loss of sense of smell or taste (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 COVID Test and Trace Cases 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 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 and over) who had tested positive for COVID-19 and who reached day 10 of their self-isolation period on 7 March 2021 or 9 March 2021. Respondents were contacted by telephone and all answers are self-reported.

This is the second bulletin in this series. The first wave of the survey was conducted as a pilot using a different sampling methodology and the estimates presented were not weighted. As a result, the data contained in this second bulletin are of better quality but are not directly comparable with the data presented in the first bulletin of the series.

The statistics contained in this bulletin are Experimental Statistics.

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 for 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 that is 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 testing positive

The range above 10 days for the length of self-isolation 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.

Adherence with self-isolation requirements

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

• did not leave their home during self-isolation, except to get or return a test for 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 adhered to the requirements if they did so because of exceptional circumstances. This means a small number of individuals may be miscategorised as non-adherent.

For those who reported having a high temperature, a new continuous cough or loss of sense of taste or smell prior to their test, adherence is measured from the onset of symptoms. Not all respondents reported having these symptoms. For respondents who did not report one of these three symptoms, adherence is measured from the date of a positive test result.

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.

For further information please see The Health Protection (Coronavirus, Restrictions) (England) Regulations 2020.

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.

This definition differs slightly from the definition of a contact for the purpose of NHS Test and Trace. For more information see guidance for contacts of people with confirmed coronavirus (COVID-19) infection who do not live with the person.

Estimates for Wave 2

The second wave of data was collected between 8 and 13 March 2021. The number of respondents was 1,122. The sample was stratified to be representative of the age, sex and regional distribution of the population being sampled.

Of the potential respondents who were successfully contacted by an interviewer, the response rate was 45%. When including cases where contact was attempted but not made, the response rate was 16%.

A low response rate can be expected as the target population was likely unwell with COVID-19 and so less likely to participate.

Percentages in this report are based on weighted counts that are representative of the population of adults (aged 18 years or over) who had tested positive for COVID-19 and began their self-isolation period between 8 February and 7 March 2021. They are also weighted to address age, sex and regional bias in response rates.

As with all surveys, these estimates have an associated margin of error. 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.

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 tested positive for COVID-19 and people they have been in contact with. 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.

The majority (95%) 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 six days.

The main strengths of the COVID Test and Trace Cases 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
• percentages are based on weighted counts representative of the population
• assessment of behaviour at three stages of the self-isolation period
• 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 COVID Test and Trace Cases Insights Survey include:

• 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

• only participants who appear in NHS Test and Trace's database were invited to take part, which will exclude people who have the coronavirus (COVID-19) but who do not request a test

• respondents may be unwilling to report illegal behaviour, for example, leaving the house during a self-isolation period; this is also known as social-desirability bias

• 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 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