Developing a Health Literacy Scale for adults in Hong Kong: A modified e-Delphi study with healthcare consumers and providers.

INTRODUCTION: Health literacy (HL) refers to individuals' abilities to process and use health information to promote health. This study aimed to develop the first HL measurement tool for the Chinese Hong Kong population.

METHODS: A two-phase methodology was adopted. In Phase I, evidence synthesis with a deductive method was conducted to formulate the item list from the literature. In Phase II, a modified e-Delphi survey was conducted among stakeholders (i.e., healthcare providers and healthcare consumers) to confirm the content validity of the item list. The stakeholders were invited to rate the relevance of each draft item on a 4-point scale and provide suggestions for revisions, removal or adding new items.

RESULTS: In Phase I, a total of 34 items covering functional, interactive and critical HL were generated. In Phase II, to obtain a balanced view from experts and laypeople, healthcare professionals (n = 12) and consumers (n = 12) were invited to participate in the Delphi panel. The response rates of the three rounds were 100%. After the third round, the consensus was reached for 31 items, and no further comments for adding or revising items were received. All items exhibited excellent content validity (item content validity index: 0.79-1.00; K*: 0.74-1.00).

CONCLUSIONS: A Health Literacy Scale for Hong Kong was developed. Compared with existing HL scales, the scale fully operationalized the skills involved in functional, interactive and critical HL. The Delphi study shows evidence supporting the high content validity of all items in the scale. In future studies, these items should undergo rigorous testing to examine their psychometric properties in our target population groups. By illuminating the details in the development process, this paper provides a deeper understanding of the scale's scope and limitations for others who are interested in using this tool.

PATIENT OR PUBLIC CONTRIBUTION: Public as healthcare consumers, in addition to healthcare providers, were involved in developing a new HL scale for this study. The input from the public contributed to examining the scale's content validity by judging whether all items reflected the skills that they need to find and use health-related information in their daily life.