Developing a measurement instrument for physical activity‑related health literacy (PA‑HL): results from an eDelphi and cognitive interviews

Using the health literacy (HL) framework proposed by Sørensen et al. (BMC Public Health 12:80, 2012), this study aimed to develop a tool for measuring information processing competence focused on physical activity (PA). This paper presents results from an approach using the online Delphi (eDelphi) method along with cognitive interviews for the development of a comprehensive physical activity-related HL measurement instrument (PA-HL). PA is a major determinant in preventing noncommunicable diseases and promoting health. Access to and appropriate use of evidence-based PA information is important for making informed decisions favoring PA, particularly in cases of an overabundance of information. Here, a two-stage development process was applied: (1) A three-round eDelphi strategy was employed with HL and PA experts, where items were rated according to relevance and comprehensibility. Consensus was operationalized as an item content validity index; the second round incorporated an online group workshop. (2) Cognitive interviews were conducted with adult participants, utilizing think-aloud and probing techniques. The item pool was analyzed utilizing a questionnaire appraisal coding scheme. The preliminary measurement instrument consisted of 60 items. After revision through both stages, it was reduced to 33 items. Most changes addressed undefined terms and overly complex questions. Cognitive interviews suggested the addition of five items and clearly distinguishing between “apply” and “decide” competencies to ensure conceptual clarity. The eDelphi study confirmed high content validity, while cognitive interviews demonstrated that most items were well understood but required linguistic simplification and shortening of lengthy or complex items. The item pool strongly focused on information processing competencies which involve decision-making, rather than behavior itself. Future research will psychometrically evaluate the PA-HL measurement instrument.