title: Factorial structure and long-term stability of the Autonomy Preference Index.
abstract: The autonomy preference index scale (API) has been designed to measure patient preference for 2 dimensions of autonomy: Their desire to take part in making medical decisions (decision making, [DM]) and their desire to be informed about their illness and the treatment (information seeking; [IS]). The DM dimension is measured by 6 general items together with 9 items related to 3 clinical vignettes (3 × 3 items). The IS dimension is measured by 8 items. While the API is widely used, a review of literature has identified several inconsistencies in the way it is scored. The first aim of this study was to determine the best scoring structure of the API on the basis of validity and reliability evidence. The second aim was to investigate the long-term stability of API scores. Two-hundred and 85 patients with a diagnosis of psychosis were assessed as they were about to be discharged from involuntary psychiatric hospitalization and they were reassessed after 6 and 12 months. Confirmatory factor analysis (CFA) revealed that a 3-factor solution was most adequate and that 2 distinct DM subscales should be preferred to 1 total DM score. While internal consistency estimates of the 3 subscales were good, the long-term stability of API scores was only modest. Multigroup-CFA revealed scalar invariance indicating API scores kept the same meaning longitudinally. In conclusion, a 3-factor structure seemed to be most adequate for the API scale. Long-term stability estimates suggested that clinicians should regularly assess patients' preferences for autonomy because API scores fluctuate over time. (PsycINFO Database Record
authors.affiliation: Service of Community Psychiatry.
authors.forename: Stephane
authors.initials: S
authors.lastname: Morandi
authors.affiliation: Service of Community Psychiatry.
authors.forename: Philippe
authors.identifier: 0000-0002-2273-6241
authors.initials: P
authors.lastname: Golay
authors.affiliation: United Kingdom Nuffield Department of Primary Care Health Sciences, and Centre for Statistics in Medicine, University of Oxford.
authors.forename: Maria
authors.initials: M
authors.lastname: Vazquez-Montes
authors.affiliation: Health Services Research Unit, Akershus University Hospital.
authors.forename: Jorun
authors.identifier: 0000-0001-5842-2845
authors.initials: J
authors.lastname: Rugkåsa
authors.affiliation: Social Psychiatry Group, Department of Psychiatry, University of Oxford.
authors.forename: Andrew
authors.initials: A
authors.lastname: Molodynski
authors.affiliation: Social Psychiatry Group, Department of Psychiatry, University of Oxford.
authors.forename: Ksenija
authors.initials: K
authors.lastname: Yeeles
authors.affiliation: Social Psychiatry Group, Department of Psychiatry, University of Oxford.
authors.forename: Tom
authors.initials: T
authors.lastname: Burns
mesh_terms: D000328:Adult; D003657:Decision Making; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D057226:Information Seeking Behavior; D008297:Male; D008875:Middle Aged; D010358:Patient Participation / Q000523:psychology*; D057240:Patient Preference / Q000523:psychology*; D026684:Personal Autonomy; D011618:Psychotic Disorders / Q000523:psychology* / Q000628:therapy; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000628:therapy; D012565:Schizophrenic Psychology; D011795:Surveys and Questionnaires