A Scoping Review of Health Literacy Measurement in U.S. Interventions: Trends, Tools, and Gaps

Background: Health literacy is a critical determinant of health outcomes, yet considerable variability exists in how it is measured across intervention studies. This scoping review article systematically mapped health literacy measurement tools and implementation reporting practices in United States-based interventions published between 2014 and 2024, with particular attention to validated and nonvalidated instruments and their application across diverse populations and settings. Methods: Following Joanna Briggs Institute guidance and Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines, we searched Ovid MEDLINE in January 2025 for studies describing health literacy interventions focusing on health care providers, patients, educators, or community organizations in the U.S. Two independent reviewers screened records and extracted data using the Population-Concept-Context framework. Implementation outcomes were assessed using the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-

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framework to evaluate reporting of Reach, Effectiveness, Adoption, Implementation, and Maintenance dimensions. Key Results: Of 117 included studies, most targeted health care patients, with strong representation of racial and ethnic groups but limited inclusion of non-English speakers. Health literacy measurement was reported in 71 studies, with only 49 employing validated instruments. The Newest Vital Sign, eHealth Literacy Scale, and RE-

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were most frequently used. Nearly all studies reported effectiveness with statistically significant results, predominantly measuring behavioral rather than clinical outcomes. RE-

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analysis revealed substantial reporting gaps, particularly in demographic details, implementation fidelity, cost documentation, and maintenance planning. Only 18% of studies reported fidelity and fewer than 10% described sustainability strategies. Discussion: While health literacy intervention research has grown substantially, significant inconsistencies in measurement practices and implementation reporting limit comparability and translation into practice. The field requires greater standardization in measurement approaches, more comprehensive demographic reporting to assess equity impacts, and systematic application of implementation science frameworks from intervention inception. Improved reporting standards are essential to accelerate translation of health literacy research into sustainable, equitable practice.