Abstract
Telehealth has emerged as a cornerstone of modern healthcare delivery, yet its efficacy is often compromised by design barriers that disproportionately affect low-literacy patient populations. This study investigates the relationship between telehealth interface usability and virtual visit completion rates among low-literacy patients using a mixed-methods evaluation framework. We conducted a mixed usability assessment involving one hundred and eighty-six participants categorized as having low health and functional literacy. Usability was measured using quantitative metrics, including task completion time, error rates, and System Usability Scale scores, alongside qualitative thematic analysis of retrospective think-aloud sessions. Predictive modeling, specifically logistic regression and random forest classification, was employed to determine which usability factors most strongly predict successful clinical visit completion. The results demonstrate that cognitive friction, navigation complexity, and icon ambiguity are major inhibitors of visit completion. The predictive model identified task completion time during onboarding and subjective cognitive load as the strongest predictors of overall visit completion. These findings suggest that tailoring telehealth user interfaces to the cognitive needs of low-literacy patients is critical to reducing health disparities and ensuring equitable access to digital medicine.References
1. Kuepfer, L.; Niederalt, C.; Wendl, T.; Schlender, J.F.; Willmann, S.; Lippert, J.; Block, M.; Eissing, T.; Teutonico, D. Applied Concepts in PBPK Modeling: How to Build a PBPK/PD Model. CPT Pharmacomet. Syst. Pharmacol. 2016, 5, 516–531.
2. Czuba, L.C.; Malhotra, K.; Enthoven, L.; Fay, E.E.; Moreni, S.L.; Mao, J.; Shi, Y.; Huang, W.; Totah, R.A.; Isoherranen, N.; et al. CYP2D6 Activity Is Correlated with Changes in Plasma Concentrations of Taurocholic Acid during Pregnancy and Postpartum in CYP2D6 Extensive Metabolizers. Drug Metab. Dispos. 2023, 51, 1474–1482.
3. Lou, J.Q.; Huo, B.N.; Yang, Y.; Wang, S.F.; Zhang, L.D.; Jia, Y.T.; Song, L. Physiologically Based Pharmacokinetic Modeling and Dose Optimization of Linezolid in Pediatric Patients With Renal Impairment. Drug Des. Devel. Ther. 2025, 19, 8427–8440.
4. Darwich, A.S.; Ogungbenro, K.; Vinks, A.A.; Powell, J.R.; Reny, J.L.; Marsousi, N.; Daali, Y.; Fairman, D.; Cook, J.; Lesko, L.J.; et al. Why has model-informed precision dosing not yet become common clinical reality? lessons from the past and a roadmap for the future. Clin. Pharmacol. Ther. 2017, 101, 646–656.
5. Tonka, J.; Schyns, M. The Digital Twin Concept: A Definition Attempt; University of Liège (ULiège): Liège, Belgium, 2021.
6. Tsantili-Kakoulidou, A.; Demopoulos, V.J. Drug-like Properties and Fraction Lipophilicity Index as a combined metric. ADMET DMPK 2021, 9, 177–190.
7. Silva, A.; Mourão, J.; Vale, N. Molecular Precision Medicine: Application of Physiologically Based Pharmacokinetic Modeling to Predict Drug-Drug Interactions Between Lidocaine and Rocuronium/Propofol/Paracetamol. Int. J. Mol. Sci. 2025, 26, 1506.
8. Curry, L.; Alrubia, S.; Bois, F.Y.; Clayton, R.; El-Khateeb, E.; Johnson, T.N.; Faisal, M.; Neuhoff, S.; Wragg, K.; Rostami-Hodjegan, A. A guide to developing population files for physiologically-based pharmacokinetic modeling in the Simcyp Simulator. CPT Pharmacomet. Syst. Pharmacol. 2024, 13, 1429–1447.
9. Saeedi, M.; Eslamifar, M.; Khezri, K.; Dizaj, S.M. Applications of nanotechnology in drug delivery to the central nervous system. Biomed. Pharmacother. 2019, 111, 666–675.
10. Fendt, R.; Hofmann, U.; Schneider, A.R.P.; Schaeffeler, E.; Burghaus, R.; Yilmaz, A.; Blank, L.M.; Kerb, R.; Lippert, J.; Schlender, J.F.; et al. Data-driven personalization of a physiologically based pharmacokinetic model for caffeine: A systematic assessment. CPT Pharmacomet. Syst. Pharmacol. 2021, 10, 782–793.
11. Barr, S.; Hill, E.W.; Bayat, A. Functional Biocompatibility Testing of Silicone Breast Implants and a Novel Classification System Based on Surface Roughness. J. Mech. Behav. Biomed. Mater. 2017, 75, 75–81.
12. Lehmann, E.L. The Fisher, Neyman-Pearson Theories of Testing Hypotheses: One Theory or Two? J. Am. Stat. Assoc. 1993, 88, 1242–1249.
13. Radke, C.; Horn, D.; Lanckohr, C.; Ellger, B.; Meyer, M.; Eissing, T.; Hempel, G. Development of a Physiologically Based Pharmacokinetic Modelling Approach to Predict the Pharmacokinetics of Vancomycin in Critically Ill Septic Patients. Clin. Pharmacokinet. 2017, 56, 759–779.

This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2026 Authors
