The relative incidence of COVID-19 in healthcare workers versus non-healthcare workers: evidence from a web-based survey of Facebook users in the United States.

Background: Healthcare workers are at the forefront of the COVID-19 pandemic and it is essential to monitor the relative infection rate of this group, as compared to workers in other occupations. This study aimed to produce estimates of the relative incidence ratio between healthcare workers and workers in non-healthcare occupations. Methods: Analysis of cross-sectional data from a daily, web-based survey of 1,788,795 Facebook users from September 6, 2020 to October 18, 2020. Participants were Facebook users in the United States aged 18 and above who were tested for COVID-19 because of an employer or school requirement in the past 14 days. The exposure variable was a self-reported history of working in healthcare in the past four weeks and the main outcome was a self-reported positive test for COVID-19. Results: On October 18, 2020, in the United States, there was a relative COVID-19 incidence ratio of 0.7 (95% UI 0.6 to 0.8) between healthcare workers and workers in non-healthcare occupations. Conclusions: Currently in the United States, healthcare workers have a substantially and significantly lower COVID-19 incidence rate than workers in non-healthcare occupations.