Mild symptoms, being unsure of testing locations, and other certain demographic factors have been identified as barriers to COVID-19 testing in the United Kingdom, according to a new study of more than 4 million adults through the U.K.

Testing remains a crucial component of the COVID-19 public health response. In the U.K., free PCR COVID-19 tests are offered to people with any of three symptoms: a high temperature, a new, continuous cough, or a change in their sense of smell or taste. However, more than a quarter of people in the U.K. reporting these symptoms don’t get tested.

The study was published in the open-access journal PLOS Global Public Health by Christina M. Astley, MD, ScD, of Boston Children’s Hospital, US, and colleagues from King’s College London.

In the new study, Astley and colleagues analyzed data on 4.3 million people enrolled in the U.K. Zoe COVID Symptom Study, who use a smartphone app to self-report COVID symptoms and test results. They sent follow-up surveys at the end of 2020 to nearly 5,000 people who reported COVID-19 symptoms but no test. The researchers also studied more than 700,000 responses, received between April 2020 and February 2021, from U.K. participants of the University of Maryland Global COVID-19 Trends and Impact Survey (UMD-CTIS), an ongoing survey.

The proportion of Zoe participants reporting COVID-19 testing among those noting symptoms has increased over time, from less than 20% in April 2020 to more than 70% in January 2021, the study found. The odds of a symptomatic person not testing were higher for those with just one symptom compared to more symptoms (27.1% versus 14.6%), and for those with symptoms lasting two or fewer days compared to those with longer-lasting symptoms (30.1% vs 14.6%). Overall, 40.4% of survey respondents were not able to name all three test-qualifying symptoms. Symptom identification decreased for every decade of age. Amongst symptomatic UMD-CTIS respondents who wanted to test but did not have a test, not knowing where to go was the most cited factor (32.4%); this increased for each decade older for every four years fewer of education

The authors conclude that greater efforts and improved messaging are needed to educate the U.K. public about testing recommendations. The findings, they say, support the need for targeted messaging to certain at-risk demographic groups, and an emphasis that even individuals with mild or transient symptoms may have COVID-19 and should get tested.

Featured image: Sign to a COVID-19 test center in the U.K. Photo: Joshua Lawrence, Unsplash