title: The use of best visual acuity over several encounters as an outcome variable: an analysis of systematic bias.
authors.affiliation: Department of Ophthalmology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Dara
authors.initials: D
authors.lastname: Koozekanani
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Covert
authors.forename: David V
authors.initials: DV
authors.lastname: Weinberg