Development and Validation of the Media Health Literacy Scale: Assessment Tool Development Study.

Background: Advancements in IT have transformed methods for accessing and conveying health-related information. While technical advancements offer more options for people to choose their preferred information sources, injudicious dissemination of incorrect or unverified health-related information by internet-based media poses a threat to society. The concepts of media health literacy (MeHlit) and eHealth literacy have emerged for assessing one's ability to understand and use health-related information from media sources. However, tools to evaluate the level of MeHlit within the domain of communication or follow a solid validation process are scarce.

Objective: This study aimed to develop a validated tool to evaluate the level of MeHlit in adults in South Korea.

Methods: A 2-step tool development process, including item development and validation processes, was carried out. At first, tool development studies were identified by a systematic review of the literature. A conceptual framework was established from the review by constructing an affinity diagram, and an item pool was generated. Face validation was conducted to assess whether the items measured MeHlit properly. Content validation was conducted to assess the overall relationship between domains by calculating the content validity index. Construct validation processes, including exploratory and confirmatory factor analyses, were completed with 1000 adults. Internal consistency of the Media Health Literacy Scale (MHLS) was assessed with Cronbach α. Concurrent validation was conducted to validate the MHLS's performance by comparing it with an established tool, the Korean version of the eHealth Literacy scale (K-eHEALS).

Results: A total of 13 published studies from the systematic review was used to develop the conceptual framework and an item pool of 65 items was created, including 3 domains (access, critical evaluation, and communication) and 9 subdomains. Through face and content validation processes, the MHLS was refined to comprise 3 domains, 6 subdomains, and 29 items. A total of 1000 participants were recruited for exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Five subdomains were identified through EFA, and CFA demonstrated a good model fit (chi-square [Cmin χ/df] under 2.659, root mean square error of approximation=0.058 [90% CI 0.053-0.062], comparative fit index=0.927, and standard root mean residual under 0.067). Following the EFA and CFA, Cronbach α scores of 0.915 and 0.932, respectively, were obtained, indicating that the tool had good reliability. A positive correlation was found between the MHLS and K-eHEALS from the concurrent validity evaluation, indicating that the MHLS can assess the target concept similarly as the K-eHEALS (Pearson correlation coefficient=0.736, P<.001).

Conclusions: The MHLS was developed and validated in a step-by-step process to assess individuals' ability to access, critically evaluate, and communicate health-related information through media platforms. This validated tool can serve in identifying deficiencies in specific MHLS areas and subsequently providing targeted education.