The rising demand for genetic counseling has prompted the implementation of various innovative service delivery models, such as patient webinars, videos, chatbots, and the integration of genetic testing into mainstream healthcare. To ensure patients receive adequate information for informed decision-making, validated measures to assess these models are essential but currently limited in the setting of inherited heart disease. We aimed to develop and initiate validation of a cardiac knowledge scale, as part of the Multidimensional Model of Informed Choice measure, to assess whether patients (probands and family members) with inherited cardiomyopathies, arrhythmias, and aortopathies are provided with sufficient knowledge to make informed decisions about genetic testing. Content expert genetic counselors identified eight core concepts addressed during genetic counseling sessions
from these, eight true/false knowledge questions were created. Questions were reviewed by 22 international cardiac genetics counselors with additional changes made. Initial validation steps of the knowledge scale were conducted at two sites: the Edmonton Medical Genetic Clinic, University of Alberta Hospital in Edmonton, Canada, and the Genetic Heart Disease Clinic, Royal Prince Alfred Hospital in Sydney, Australia. Face validity was evaluated through nine patient interviews, resulting in minor revisions to four questions and major revisions to one question. An additional five patient interviews were conducted to evaluate the revised questions. The core concepts addressed in each question were further evaluated in the context of patient decision-making about genetic testing. All participants described the eight concepts as either helpful or essential in their decision-making process. The cardiac knowledge scale is a promising measure created to evaluate the informed choice of patients and their families affected by an inherited heart condition. The next step of validation includes trialing the cardiac knowledge scale with a real-world sample of patients deciding about genetic testing for inherited heart disease.