Fewer than one in five people requested a Covid-19 test if they had symptoms, according to a large study of the Test and Trace system.
Experts found that over the past year only half of people could identify the main coronavirus symptoms, which include a cough, high temperature and loss of taste or smell, the BMJ reports.
Just 18% of those with symptoms said they had requested a test, while only 43% with symptoms in the previous seven days adhered to full self-isolation.
Labour seized on the research to urge ministers to do more to fix Test and Trace, run by Tory peer Dido Harding, and to provide greater financial support for those who can’t afford to self isolate for 10 days.
But the government pointed to survey data from the Office of National Statistics (ONS) last week that showed that 86% of people testing positive for coronavirus are now fully complying with self-isolation guidance for their full isolation period.
Data showed 90% of the contacts reached by NHS Test and Trace are fully adhering with the rule.
The BMJ reported that the study, which included work by the Public Health England (PHE) behavioural science team at Porton Down in Wiltshire, was based on 74,697 responses to online surveys from 53,880 people aged 16 or older living in the UK.
The research covered 37 survey “waves” carried out from March 2 last year to January 27 this year, with about 2,000 participants in each wave.
The results showed that only 52% of people could identify the main symptoms of Covid-19, and this did not really improve as time went on.
Across all waves, 43% of people adhered to rules around self-isolation, though this improved in January to 52%.
Men, younger people and those with young children were less likely to self-isolate, as were those from more working-class backgrounds, people experiencing greater financial hardship, and those working in key sectors.
Common reasons for not fully self-isolating included to go to the shops or work, for a medical need other than Covid-19, to care for a vulnerable person, to exercise or meet others, or because symptoms were only mild or got better.
Just 18% of people requested a Covid test if they had experienced symptoms in the previous seven days, despite around three times as many saying they intended to do so if they developed signs of coronavirus.
Intention to share details of close contacts with NHS Test and Trace was 79%, the study found, but there was some hesitancy around whether data was secure and confidential, and whether the contact tracing system was accurate and reliable.
The experts, including from King’s College London, said: “With such low rates for symptom recognition, testing, and full self-isolation, the effectiveness of the current form of the UK’s test, trace, and isolate system is limited.”
The team concluded: “Levels of adherence to test, trace, and isolate are low, although some improvement has occurred over time.
“Practical support and financial reimbursement are likely to improve adherence.
“Targeting messaging and policies to men, younger age groups, and key workers might also be necessary”.
Shadow health minister Justin Madders told HuffPost UK: “This is yet another damning indictment of the way test and trace has been run during the Covid crisis.
“Given the tsunami of evidence presented about the financial difficulties people face when self isolating it is becoming increasingly perplexing as to why the government fail to address this properly when it could have a significant impact on reducing transmission.
“When we finally have the inquiry into why we have had one of the highest death tolls in the world they will need to answer why they have repeatedly ignored the warnings on test and trace.”
A Department for Health and Social Care spokesperson said: “Since last May, NHS Test and Trace has contacted 3.2 million people who tested positive, and another 6.4 million of their contacts.
“Behind these numbers are countless lives saved and the latest ONS statistics show that when people are asked to self-isolate, the overwhelming majority do so.
“It is vital that people continue to do their bit by isolating when they are asked to. As the prevalence of coronavirus falls, our testing and tracing system becomes more important in identifying and suppressing local outbreaks while also responding rapidly to the threat of new variants.”
In March, MPs on the Public Accounts Committee said the impact of NHS Test and Trace is still unclear, despite the UK government setting aside £37 billion for it over two years.
Its report criticised an over-reliance on consultants, with some paid more than £6,600 a day.
It also questioned a failure to be ready for a surge in demand for tests last September, and NHS Test and Trace not meeting its target to turn around face-to-face tests within 24 hours.
A study from the National Audit Office (NAO) in December also criticised the scheme, saying it had not yet achieved its objectives.
The NAO said it was “very important that testing and tracing is able to make a bigger contribution to suppressing the infection than it has to date”.