Covid-19 symptom checkers may have led people to stay home when they need medical attention, according to a new study.
The authors said that if the NHS 111 Covid-19 symptom checker is used as the “sole starting point for contact with health care providers,” it could cause the search for care to be delayed, which could increase the risk of illness or death.
For example, the symptom reviewer would instruct a 72-year-old person who has had a fever and cough for a week “to stay home without clinical, nursing, or medical contact,” according to scientists from the Gibraltar Health Authority.
However, NHS Digital said the study was “based on an early version of the tool.”
The study, published in the journal BMJ Health and Care Informatics, examined how national symptom reviewers worked against simulated cases of Covid-19 that differed in risk and severity.
National symptom reviewers have been introduced in many countries to reduce the burden on health services.
People can enter symptoms – usually online or through an app – and from the information entered, the algorithm provides some advice.
It is hoped that these reviews will effectively identify those who would benefit from a doctor’s evaluation.
Scientists set out to study the symptom checkers, which were created by five different nations – Singapore, Japan, Norway, the UK (although the English symptom checker), and the US.
The researchers developed 52 simulated cases with different risk factors and entered them into the symptom reviewers.
The authors looked at how many of the cases would have been referred to patients for help.
Singapore had the highest remittance rate at 88% and the US had the lowest at 38%. The NHS system examined 44% of cases for exposure to health care.
The authors said the US and English systems tried “significant numbers” of “stay at home” cases that would normally have required early clinical evaluation.
“The UK 111 Covid-19 Symptom Checker has frequently tested possible severe Covid-19 and bacterial pneumonia to stay home without follow-up and has likely delayed treatment for sepsis and severe Covid-19,” the authors wrote.
They added, “Symptom reviewers in the low-fatalities (Singapore and Japan) performed direct clinical assessment in twice as many cases as the higher-fatalities (US and UK).
“Of clinical concern was the failure of the US and UK symptom checkers to simulate cases simulating bacterial pneumonia, sepsis and severe Covid-19 in contact with healthcare providers.”
They said the wording of some questions on the 111 Symptom Tracker encourages self-reporting on lower disease categories.
“Our case simulation has shown that answering the moderate answer still causes patients to self-isolate out of contact with healthcare,” they wrote.
“Therefore, patients with a cough and fever would have to be so seriously ill for seven days that they cannot do anything they normally do to establish clinical contact.
“Our case simulation study shows that both the ‘111 Covid-19 Symptom Checker’ and the ‘CDC Coronavirus Symptom Checker’, when used as the sole starting point for healthcare contact, are likely to present serious illnesses with appropriate care delay. and as such likely to confer an increased risk of morbidity and mortality.
“Both symptom checkers maintain a high threshold for referral to clinical contact and the majority of patients attempt to stay at home without clinical contact.”
NHS Digital said in a statement: “NHS 111 online is not a diagnostic tool. It allows people to rate their symptoms and pointers to other NHS services as needed.
“This simulation study was based on an early version of the tool.
“It has been continuously revised and updated over the past year to respond to new scientific information, government guidelines and public health strategies.”