title: Constructing an Index for the Subjective Well-being Under Neuroleptics scale (SWN), short form: applying structural equation modeling for testing reliability and validity of the index.
abstract: Structural equation modeling (SEM) has been widely used in psychology and sociology for testing validity of measurement instruments. However, this statistical technique has so far played minor role in quality-of-life research. The main objective of this paper is to demonstrate the potential of SEM for constructing and testing the validity of a Subjective Well-being under Neuroleptics (SWN) index for patients with schizophrenia. For these purposes, data from the GEO study (Gesundheitsökonomische Evaluation von Olanzapin in Deutschland; Health economics study of olanzapine in the treatment of schizophrenia in Germany) were used. The GEO is a prospective, comparative, noninterventional, observational study. A total of 646 participants treated with either olanzapine (n = 416) or haloperidol (n = 230) were enrolled in the study; 360 patients were available for factor analyses. The short (20-item) form of the SWN scale was administered to assess patients' perspectives on their quality of life. The structural equation models (SEMs) were then applied to construct 5- and 10-item indexes based on SWN. The data indicate that the 5-item index is the most time-saving approach for evaluating perceptions of well-being (and thus, quality of life) among patients with schizophrenia. The application of SEM showed no appreciable loss of validity of this index.
authors.affiliation: Institut für Politikwissenschaften, FB 03 Sozial- und Kulturwissenschaften, Justus Liebig Universität Giessen, Karl-Glöckner-Strasse 21 E, 35394 Giessen, Germany. Peter.Schmidt@sowi.uni-giessen.de
authors.forename: Peter
authors.initials: P
authors.lastname: Schmidt
authors.forename: Johannes
authors.initials: J
authors.lastname: Clouth
authors.forename: Lars
authors.initials: L
authors.lastname: Haggenmüller
authors.forename: Dieter
authors.initials: D
authors.lastname: Naber
authors.forename: Ursula
authors.initials: U
authors.lastname: Reitberger
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001569:Benzodiazepines / Q000627:therapeutic use; D005858:Germany; D006220:Haloperidol / Q000627:therapeutic use; D006801:Humans; D015233:Models, Statistical; D000077152:Olanzapine; D010549:Personal Satisfaction; D011446:Prospective Studies; D011594:Psychometrics; D012559:Schizophrenia / Q000188:drug therapy*; D011795:Surveys and Questionnaires
chemical_list: D014150:Antipsychotic Agents; D001569:Benzodiazepines; D006220:Haloperidol; D000077152:Olanzapine