Participant engagement in a national longitudinal study of COVID-19: Insights from the INSPIRE study - Kris Pui Kwan Ma; Tracy Stober; Michael Gottlieb; Rachel E. Geyer; Kristin Rising; Sharon Saydah; Michelle Santangelo; Kristyn Gatling; Dylan Grau; Ralph C. Wang; Juan Carlos Montoy; Ahamed Idris; et al. (PLoS ONE)