title: The decision evaluation scales.
abstract: There are several instruments to assess how patients evaluate their medical treatment choice. These are used to evaluate decision aids. Our objective is to investigate which psychological factors play a role when patients evaluate their medical treatment choices. A pool of 36 items was constructed, covering concepts such as uncertainty about and satisfaction with the decision, informed choice, effective decision making, responsibility for the decision, perceived riskiness of the choice, and social support regarding the decision. This pool was presented to patients at high risk for breast and ovarian cancer, awaiting a genetic test result, and facing the choice between prophylactic surgery or screening. Additional measures were assessed for validation purposes. Factor and Rasch analyses were used for factor and item selection. Construct validity of emerging scales was assessed by relating them with the additional measures. Three factors summarised the psychological factors concerning decision evaluation: Satisfaction-Uncertainty, Informed Choice, and Decision Control. Reliabilities (Cronbach's alpha) of the three scales were 0.79, 0.85, and 0.75, respectively. Construct validity hypotheses were confirmed. The first two scales were similar to previously developed scales. Of these three scales, the Decision Control scale correlated most strongly with the well-being measures, was associated with partner's agreement and physician's preferences as perceived by patients, and with a negative emotional reaction to the information material. In conclusion, the Decision Control scale is a new scale to evaluate decision aids, and it appears to be rooted in health psychological theories.
authors.affiliation: Medical Technology Assessment, University Medical Centre Nijmegen, Postbus 9101, 6500 HB Nijmegen, The Netherlands. p.stalmeier@mta.umcn.nl
authors.forename: Peep F M
authors.initials: PF
authors.lastname: Stalmeier
authors.forename: Marielle S
authors.initials: MS
authors.lastname: Roosmalen
authors.forename: Lia C G
authors.initials: LC
authors.lastname: Verhoef
authors.forename: Josette E H M
authors.initials: JE
authors.lastname: Hoekstra-Weebers
authors.forename: Jan C
authors.initials: JC
authors.lastname: Oosterwijk
authors.forename: Ute
authors.initials: U
authors.lastname: Moog
authors.forename: Nicoline
authors.initials: N
authors.lastname: Hoogerbrugge
authors.forename: Willem A J
authors.initials: WA
authors.lastname: van Daal
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000235:genetics / Q000628:therapy*; D002755:Choice Behavior; D003661:Decision Support Techniques; D005163:Factor Analysis, Statistical; D005260:Female; D005820:Genetic Testing / Q000523:psychology; D006785:Hospitals, University; D006801:Humans; D007258:Informed Consent; D007389:Internal-External Control; D008875:Middle Aged; D009341:Negativism; D009426:Netherlands; D010051:Ovarian Neoplasms / Q000235:genetics / Q000628:therapy*; D010353:Patient Education as Topic; D010358:Patient Participation / Q000379:methods / Q000523:psychology*; D017060:Patient Satisfaction; D011594:Psychometrics; D018570:Risk Assessment; D012944:Social Support; D011795:Surveys and Questionnaires / Q000592:standards*; D035501:Uncertainty