Preliminary Validation of a Novel Genetic Knowledge Scale for Familial Hypercholesterolemia: Evaluation of Face Validity and Core Concepts

Facilitating patient-informed decision making is central to the genetic counseling practice. The Multidimensional Model of Informed Choice (MMIC) evaluates informed decisions in genetic testing, but validated MMIC measures for inherited cardiac conditions are lacking. This study aimed to begin validating an 8-item true/false knowledge scale specific to familial hypercholesterolemia (FH). Once validated, this scale will form part of an MMIC measure to assess informed choice in the context of genetic testing for this condition. Ten semi-structured cognitive interviews were conducted to examine face validity and the importance of concepts within the scale. A traffic light coding system was used to analyze participant responses. All participants interpreted the items correctly, and minor revisions were made to improve the clarity of six items. Most participants (n = 9) considered all concepts covered by the knowledge scale to be either helpful or necessary to make a decision about genetic testing for FH. This study initiated the validation of a novel genetic knowledge scale specific to FH, to be used as part of a larger measure to assess patient informed choice in the context of genetic testing for this condition. The development and future validation of the genetic knowledge scale for FH can be used in novel research targeted at maximizing patient informed choice among this patient population.