Relationship between socioeconomic, demographic, health and social characteristics and ability to access reliable information on herbal and food supplements: analysis of Thai Health Literacy Survey 2019.

Background: The consumption of herbal and food supplements attributing to health expenditures in Thailand has been increasing over the years. However, information on herbal and food supplement products can make it difficult for some people with limited health literacy to use. Evidence from previous studies outside Thailand shows that SES disadvantaged groups are more likely to have limited health literacy compared with their counterparts with advantaged SES. The present study adds to this body of knowledge through an exploration of health literacy competencies related to herbal and food supplement consumption to determine what competency would be most problematic among Thai people. The study also investigated the influences of demographic and socio-economic factors on the most problematic health literacy competency on herbal and food supplements.

Methods: The THL-S used a stratified three-stage-sampling to draw a sample of Thais aged 15 years and above. Participants were interviewed with a questionnaire of 34 items measuring health literacy and 8 items measuring behavioural practices. Responses to questions on accessing, understanding, communicating, and making decisions related to herbal and food supplement consumption were analysed. A logistic regression model was used to explore the association between having difficulties in accessing information and participant's socio-economic factors.

Results: Levels of difficulties the participants experienced varied among their health literacy competencies. Accessing reliable information was found to be the most problematic health literacy competency faced by respondents (48%), followed by asking healthcare providers about herbal products and food supplements (41%). Significant differences in the ability to access reliable information on herbal and food supplements were found to be based on differences in: education, income levels, occupation, insurance scheme coverage, age, sex, reading ability, writing ability, chronic diseases, wearing eyeglasses or lenses, hearing impairment, and having a community leading role.

Conclusions: Accessing reliable information on herbal and food supplements has been found to be the most difficult health literacy competency among respondents to the survey, particularly vulnerable consumers in the society such as people with hearing impairment or having limited overall literacy competencies. Therefore, health literacy programs might be developed to build health literacy competencies and empower vulnerable consumers for reasonable use of herbal and food supplements.