title: THE AUTHORS REPLY.
authors.affiliation: Centre for Health Evaluation and Outcome Sciences (CHÉOS), St. Paul's Hospital, Vancouver, BC, Canada.
authors.forename: Mohammad Ehsanul
authors.initials: ME
authors.lastname: Karim
authors.affiliation: Department of Statistics, Faculty of Science, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Gustafson
authors.affiliation: Department of Statistics, Faculty of Science, University of British Columbia, Vancouver, BC, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Petkau
authors.affiliation: Division of Neurology, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.|Brain Research Centre, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Helen
authors.initials: H
authors.lastname: Tremlett