The evolving usefulness of the Test-Negative Design in studying risk factors for COVID-19 due to changes in testing policy

Jan P Vandenbroucke, Elizabeth B Brickley, Christina M. J. E. Vandenbroucke-Grauls +1

This paper is a short extension of our previous paper [arXiv:2004.06033] about the use of the Test-Negative design to study risk factors for COVID-19 [See: PubMed and ArXiv referen…