title: Introduction.
authors.affiliation: Massachusetts General Hospital and Harvard Medical School, USA. Electronic address: zirui_song@post.harvard.edu.
authors.forename: Zirui
authors.initials: Z
authors.lastname: Song
authors.affiliation: Vanderbilt University Medical Center, USA.
authors.forename: Melinda
authors.initials: M
authors.lastname: Buntin
authors.affiliation: University of Pennsylvania, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Werner
authors.affiliation: Centers for Medicare and Medicaid Innovation, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Baron