Development of the Knowledge of Genome Sequencing (KOGS) questionnaire

Objective: Whole-genome sequencing is being implemented in research and clinical care, yet tools to assess patients’ knowledge are lacking. Our aim was to develop a robust measure of whole-genome sequencing knowledge suitable for patients and other stakeholders including research participants, public, students, and healthcare professionals. Methods: An initial set of 17 items was developed via an iterative process including literature review, expert consultation, focus groups, and cognitive interviews with patients, and then administered to 243 individuals. We used exploratory factor analysis and item-response theory to confirm the psychometric suitability of the candidate items for assessing whole-genome sequencing knowledge. Results: There was a strong main component after removing 5 items with low factor loadings. Item and scale homogeneity was achieved using Mokken scale analysis. Three further items were removed because they were misfits, inverse duplicates or resulted in local dependency. The remaining nine items fitted the two-parameter logistic IRT model which achieved excellent fit to the observed data. Cronbach's alpha was 0.79 indicating acceptable reliability. Conclusion: The KOGS, developed using a rigorous psychometric approach, is a brief and reliable tool. Practice implications: The KOGS may prove useful for researchers and healthcare professionals using whole-genome sequencing with patients and other stakeholders.