title: Invited commentary.
authors.affiliation: Scientist and Director Mobility Program Clinical Research Unit, St. Michael's Hospital.
authors.forename: Dorcas
authors.initials: D
authors.lastname: Beaton
mesh_terms: D003627:Data Interpretation, Statistical; D006801:Humans; D015233:Models, Statistical; D015207:Osteoarthritis, Hip / Q000503:physiopathology*; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D017063:Outcome Assessment, Health Care; D010146:Pain / Q000503:physiopathology; D010147:Pain Measurement