Peer Review Report For: Precision medicine implementation and research-practice partnerships: implications of measurement scale differential item functioning [version 1; peer review: 1 approved, 1 not approved]

Background: Omics-based biomarkers (OBMs) inform precision medicine (PM). As omics-based technologies gradually move into clinical settings, however, a co-occurrence of biomedical research and clinical practice is likely an important variable in the implementation of PM. Currently, little is known about the implications of such research-practice co-occurrence. Methods: This study used data collected from a pilot study designed to inform a full-scale PM implementation study through the validation of the measurement tool. It applied item response theory (IRT) methods to assess the tool’s reliability and measurement invariance across two study subgroups associated with research and practice settings. Results: The study sample consisted of 31 participants. Measurement invariance assessment was through differential item functioning (DIF) analysis with bootstrapping through Monte Carlo simulation. Overall, 13 out of 22 items that formed the PMI scale had DIF at significance level α=0.25. Item response functions (IRFs) revealed how each subgroup members responded to scale items and their attitudes towards factors that influence PM implementation. Conclusions: Attitudinal similarities and differences towards factors influencing PM implementation amongst those in biomedical research as compared with those in practice were established. Results indicated PM implementation knowledge that is unique and common to both groups. The study established the validity and reliability of the new PM implementation measurement tool for the two subgroups.