Methods to Adjust for Confounding in Test-Negative Design COVID-19 Effectiveness Studies: Simulation Study. - Rowley EA; Mitchell PK; Yang DH; Lewis N; Dixon BE; Vazquez-Benitez G; Fadel WF; Essien IJ; Naleway AL; Stenehjem E; Ong TC; Gaglani M; et al. (JMIR formative research, 2025)