Development and Validation of the Vanderbilt PRS-KS, an Instrument to Quantify Polygenic Risk Score Knowledge

PurposeAs polygenic risk scores (PRS) enter clinical practice, healthcare providers and the publics comprehension of PRS results are of great importance, yet poorly understood. We present the Vanderbilt Polygenic Risk Scores Knowledge Score (Vanderbilt PRS-KS), a tool to quantify PRS knowledge. MethodsThe Vanderbilt PRS-KS was developed by a team of genetic counselors and physicians to cover key conceptual facts pertaining to PRSs. We recruited (n=500) individuals with demographics representative of a U.S. sample and graduate-level healthcare students (n=74) at a large academic medical center to participate in this validation study. We evaluated the Vanderbilt PRS-KSs psychometric properties using confirmatory factor analysis (CFA) and item response theory (IRT). ResultsThe 7-item Vanderbilt PRS-KS correlated to a single latent construct on CFA ({Lambda}=0.31-0.61). The scale showed promising reliability (Cronbachs =0.66) with IRT summed scores of [&ge;]2 to [&le;]5, demonstrating reliability > 0.70. The Vanderbilt PRS-KS significantly correlated with genetic knowledge and applied PRS knowledge (r=0.55, r=0.29), and graduate-level healthcare students had significantly higher scores compared to the representative sample (p<0.01). ConclusionsThe Vanderbilt PRS-KS is a rigorously validated measure to quantify PRS knowledge.