Development of an assessment technique for basic science retention using the NBME subject exam data.

INTRODUCTION: One of the challenges in medical education is effectively assessing basic science knowledge retention. National Board of Medical Examiners (NBME) clerkship subject exam performance is reflective of the basic science knowledge accrued during preclinical education. The aim of this study was to determine if students' retention of basic science knowledge during the clerkship years can be analyzed using a cognitive diagnostic assessment (CDA) of the NBME subject exam data. METHODS: We acquired a customized NBME item analysis report of our institution's pediatric clerkship subject exams for the period of 2017-2020 and developed a question-by-content Q-matrix by identifying skills necessary to master content. As a pilot study, students' content mastery in 12 major basic science content areas was analyzed using a CDA model called DINA (deterministic input, noisy "and" gate). RESULTS: The results allowed us to identify strong and weak basic science content areas for students in the pediatric clerkship. For example: "Reproductive systems" and "Skin and subcutaneous tissue" showed a student mastery of 83.8 ± 2.2% and 60.7 ± 3.2%, respectively. CONCLUSIONS: Our pilot study demonstrates how this new technique can be applicable in quantitatively measuring students' basic science knowledge retention during any clerkship. Combined data from all the clerkships will allow comparisons of specific content areas and identification of individual variations between different clerkships. In addition, the same technique can be used to analyze internal assessments thereby creating an opportunity for the longitudinal tracking of student performances. Detailed analyses like this can guide specific curricular changes and drive continuous quality improvement in the undergraduate medical school curriculum.

Reduced preload increases Mechanical Control (strain-rate dependence) of Relaxation by modifying myosin kinetics.

Rapid myocardial relaxation is essential in maintaining cardiac output, and impaired relaxation is an early indicator of diastolic dysfunction. While the biochemical modifiers of relaxation are well known to include calcium handling, thin filament activation, and myosin kinetics, biophysical and biomechanical modifiers can also alter relaxation. We have previously shown that the relaxation rate is increased by an increasing strain rate, not a reduction in afterload. The slope of the relaxation rate to strain rate relationship defines Mechanical Control of Relaxation (MCR). To investigate MCR further, we performed in vitro experiments and computational modeling of preload-adjustment using intact rat cardiac trabeculae. Trabeculae studies are often performed using isometric (fixed-end) muscles at optimal length (Lo, length producing maximal developed force). We determined that reducing muscle length from Lo increased MCR by 20%, meaning that reducing preload could substantially increase the sensitivity of the relaxation rate to the strain rate. We subsequently used computational modeling to predict mechanisms that might underlie this preload-dependence. Computational modeling was not able to fully replicate experimental data, but suggested that thin-filament properties are not sufficient to explain preload-dependence of MCR because the model required the thin-filament to become more activated at reduced preloads. The models suggested that myosin kinetics may underlie the increase in MCR at reduced preload, an effect that can be enhanced by force-dependence. Relaxation can be modified and enhanced by reduced preload. Computational modeling implicates myosin-based targets for treatment of diastolic dysfunction, but further model refinements are needed to fully replicate experimental data.