Development and psychometric validation of the health literacy practice knowledge scale for nurses

Health literacy is a key determinant of health outcomes and a global priority under the United Nations 2030 Sustainable Development Goals. Although nurses play a pivotal role in delivering health literacy–responsive care, objective, psychometrically validated instruments for assessing nurses’ health literacy practice knowledge remain limited, particularly in Chinese-speaking contexts. This study aimed to develop and psychometrically evaluate the Health Literacy Practice Knowledge Scale for Nurses (HLPKSN) supporting competency-based education. A cross-sectional design was used. The HLPKSN was developed through literature review, item development, two rounds of Delphi review involving 11 experts, pilot testing, and psychometric evaluation. A convenience sample of 434 registered nurses in Taiwan completed an online survey in November 2024. Psychometric properties were examined using both Classical Test Theory and Rasch analysis. The final 19-item HLPKSN demonstrated acceptable internal consistency (KR-20 = 0.705), satisfactory item difficulty (mean = 0.73) and discrimination (mean = 0.34), and good Rasch model fit, with Infit and Outfit statistics falling within the acceptable range (0.7–1.3). Item reliability was 0.98 and item separation 7.27, whereas person reliability (0.59) and person separation (1.20) were lower, indicating that the scale distinguishes approximately two ability strata. The HLPKSN is a content-valid and practice-oriented instrument for assessing nurses’ health literacy practice knowledge. It provides an objective means of identifying knowledge gaps, evaluating educational interventions, and supporting competency-based nursing education and continuing professional development to strengthen health literacy–responsive nursing practice. Given the limited person separation, the scale is currently best suited to group-level assessment rather than high-stakes individual discrimination.