title: Reply to Dai et al.
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Gaines
authors.affiliation: University of North Carolina, Chapel Hill, North Carolina, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Kappelman
authors.affiliation: University of North Carolina, Chapel Hill, North Carolina, USA.
authors.forename: Millie Dascomb
authors.initials: MD
authors.lastname: Long