Executive Summary of HLS-EU Short Form Instruments Introduction and Rationale The original HLS-EU-47Q tool is recognized for its detail, allowing for a comprehensive health literacy index and 19 sub-indices . However, its primary disadvantages are that it is time-consuming for respondents and involves high administration costs . To improve efficiency, researchers developed shorter versions by selecting the most critical items while maintaining a strong correlation with the original 47-item scale . HLS-EU-Q16: The Short Form The HLS-EU-Q16 is a 16-item version designed to provide a reliable overview of health literacy when a full assessment is not feasible . Scoring System: It uses a dichotomous scale where easy or very easy answers receive 1 point, and difficult or very difficult answers receive 0 points . The total score ranges from 0 to 16 . Proficiency Levels: Results are categorized into three levels: Likely Inadequate (0 to 8 points), Likely Problematic (9 to 12 points), and Likely Sufficient (13 to 19 points, noting that 16 is the actual maximum score) . Strengths: It maintains a high correlation with the HLS-EU-47Q (r = 0.82) and is "Rasch homogeneous," making it suitable for comparisons within a single country . Limitations: It cannot analyze all sub-dimensions of health literacy and its scores do not follow a normal distribution, which limits certain statistical analyses . It is also less precise for individuals with borderline scores and cannot be used for cross-country comparisons . HLS-EU-Q6: The Short-Short Form This is the most condensed version, consisting of 6 items selected from the three domains of Health Care, Disease Prevention, and Health Promotion (2 items from each) . Scoring System: Unlike the Q16, this version uses a 4-point scale (1 = very difficult to 4 = very easy) and evaluates the result based on the Mean score . Proficiency Levels: The categories are defined as Likely Inadequate (mean less than 2.00), Likely Problematic (mean between 2.00 and 2.99), and Likely Sufficient (mean between 3.00 and 4.00) . Guidelines for Tool Selection The choice of instrument should align with the research objectives : Select HLS-EU-47Q: If health literacy is the primary focus and the study requires in-depth analysis of specific sub-dimensions . Select HLS-EU-Q16: For studies where health literacy is a main objective but economical data collection is required without the need for sub-dimension details . Select HLS-EU-Q6: When health literacy is only one of several variables in a larger study and needs to be measured with maximum speed . Regional Adaptations: HLS-Taiwan-Q12 Some regions have developed their own localized short forms. For instance, Taiwan developed a 12-item version that selects items specifically suited to its local context rather than strictly following the European item selection