title: Electronic devices and applications to track physical activity--reply.
authors.affiliation: University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Meredith A
authors.initials: MA
authors.lastname: Case
authors.affiliation: Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Volpp
authors.affiliation: Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
authors.forename: Mitesh S
authors.initials: MS
authors.lastname: Patel
mesh_terms: D056044:Actigraphy / Q000295:instrumentation*; D040421:Cell Phone; D006801:Humans; D063731:Mobile Applications; D009043:Motor Activity; D016138:Walking