Designing Health Literacy Measurement Tools: A Critical Review of Common Paths and Probable Mistakes

Background and Objective: Measuring concepts such as health literacy, either generally or specifically, in different populations requires the use of existing standard instruments or the development of new ones by the researcher. The study was conducted to critical review of common methodologies for instrument development in the health literacy. Materials and Methods:  This review article examines health literacy measurement tools with two objectives: 1) methodological review of tool design 2) review of the items used in each tool by posing this question (validity review) Do the items measure what is intended in relation to the concept of health literacy and its dimensions?”. In order to access the health literacy tools, first was referred to the site Health Literacy Tool Shed .10% of the available tools (20 item) were randomly included in the study for a deep and detailed review. Results: Finding showed, researchers employed three different approaches to the development of measurement instruments; 1) Review of literature or used the already existing instruments, 2) The qualitative approach to explain a concept and embrace it from different dimensions as well as construct the items and 3) Mix-method approach (a mixture the previous two approaches). Two mistakes include 1) interpretation error (error of qualitative content analysis, creation of categories and sub-categories from codes and meaning units) and 2) program error (error of exploiting subcategories and categories in designing and generating items and different parts of tools) reported. Conclusions: Paying attention and considering what was indicated regarding different approaches and paths as well as processes and methods can preserve researches to a large extent from the main problem that is the collection of inaccurate data due to instruments with low validity and reliability.