Cross‐Cultural Adaptation of the University of North Carolina Genomic Knowledge Scale: Translation and Psychometric Validation in Japanese Populations

This study was aimed at translating the University of North Carolina Genomic Knowledge Scale (UNC-GKS) and evaluating its reliability and validity in assessing genomic knowledge among Japanese patients who received an explanation of whole-exome sequencing (WES) in a clinical setting. The scale was translated according to the International Society for Pharmacoeconomics and Outcomes Research guidelines using forward-backward procedures with harmonization, followed by cognitive debriefing using an open-ended questionnaire. Participant feedback was qualitatively reviewed and informed revisions to the placement of the explanatory text. The participants were 189 parents of pediatric patients who had undergone, or were scheduled to undergo, WES as part of the Japanese Initiative on Rare and Undiagnosed Diseases. The UNC-GKS was translated according to the International Society for Pharmacoeconomics and Outcomes Research guidelines. A survey package including sociodemographic data, the UNC-GKS Japanese version and the 14-item Health Literacy Scale (HLS-14) was distributed via post and online between August and September 2022. A retest was conducted 2 weeks later. Internal consistency was assessed using Cronbach's α and test-retest reliability with intraclass correlation. Construct validity was examined via correlations with the HLS-14 scores and background factors. The UNC-GKS Japanese version demonstrated excellent internal consistency (Cronbach's α = 0.94) and sufficient test-retest reliability (ICC for total score = 0.90; 95% CI: 0.81-0.94; item-level ICCs ranged from 0.42 to 0.84, with no negative test-retest correlations). While content validity was ensured through a structured translation process, construct validity with HLS-14 was not supported. The UNC-GKS Japanese version is a reliable and valid instrument for assessing genomic knowledge among Japanese patients who have received an explanation of WES. Future research should explore the association between numeracy and alternative health literacy measures to better understand convergent validity.