A study published in the Lancet Public Health estimates that healthcare workers in the UK and the US are at least three times more likely to report a positive COVID-19 test compared to the general public, even after accounting for differences in testing frequency between the two groups.
The prospective, observational cohort study was carried out using self-reported data from the COVID Symptom Study smartphone app from March 24 to April 23 in the UK and from March 29 to April 23 in the US.
Among 2,035,395 community individuals and 99,795 frontline healthcare workers, there were 5,545 incident reports of a positive test. After adjusting for differences in testing frequency, the likelihood of a positive COVID-19 test was 3.4 times higher for healthcare workers.
In secondary analyses, healthcare workers who reported having inadequate PPE were 1.3 times more likely to report a positive test than those who had adequate equipment. Healthcare workers who reported reusing PPE were almost 1.5 times more likely to report a positive test than those with adequate PPE.
Risks were highest for healthcare workers caring for patients with confirmed COVID-19 without adequate PPE, being almost six times higher than those with adequate PPE who were not exposed to COVID-19 patients.
Even with adequate PPE, the risk of testing positive was almost 2.4 times greater for those caring for people with suspected COVID-19 and around five times greater for healthcare workers caring for people with confirmed COVID-19, compared with those who were not exposed to COVID-19 patients.
The prevalence of positive tests was higher in US healthcare workers compared with the UK. However, after accounting for differences in access to testing, the risk of predicted COVID-19 based on symptoms reported through the app was double that of the general population for UK-based workers compared with 1.3 times greater for US workers. The researchers say this higher infection rate could be the result of differences in the availability of PPE between the two countries.
The study has limitations that must be considered when interpreting the findings.