title: Measuring patients' preferences for participating in health care decisions: avoiding invalid observations.
authors.forename: Hilary A
authors.initials: HA
authors.lastname: Llewellyn-Thomas
mesh_terms: D003625:Data Collection / Q000379:methods*; D003657:Decision Making; D006302:Health Services Research / Q000379:methods*; D006801:Humans; D010358:Patient Participation; D017060:Patient Satisfaction