Introduction
Self-management of type 1 diabetes is a complex and demanding task, drawing on time as well as cognitive and emotional resources of the individual.1 Using these resources effectively and efficiently requires individuals to engage with healthcare professionals regularly to update and adjust knowledge and skills and to learn how to use new technologies and devices.2 Therefore, understanding health information and successful communication with healthcare providers is crucial for self-management for people with diabetes. The skills of understanding, appraising and engaging with health information is also important outside the relationships with the diabetes care team, not least with increasing information available through the internet and social media.3 Although guidelines and standards for the comprehensibility of health information and resources are being defined worldwide, research continues to demonstrate that much of the available health information does not meet these standards.4
In this context, health literacy is increasingly recognized as critical to our understanding of an individual’s resources and capability to self-manage chronic conditions. Health literacy is defined as the ‘cognitive and social skills which determine the motivation and ability of people to gain access to, understand and use information in ways which promote and maintain good health’.5 Previous studies on the importance of health literacy in diabetes management have been inconsistent.6–8 Some studies have found an association between low health literacy and low HbA1c level,9–12 whereas others did not find such association.13–16 One reason for the lack of consistency may relate to differences in measurement of health literacy, for example, use of measures that focus on health-related literacy and numeracy (ie, functional health literacy), rather than the wider range of competencies that are necessary for diabetes self-management. We use a multidimensional measure of health literacy, including ability to read, understand, and critically appraise health information and ability to navigate the health system, communicate and engage with healthcare providers. This measure offers the opportunity to explore the relationship between health literacy and diabetes management with greater precision.
Another challenge in the literature on healthy literacy is that the use of measures of literacy commonly report strong associations between patient characteristics, including educational attainment, income and health literacy.3 This is problematic as it makes it unclear whether the measurement used to asses health literacy is just a proxy measure of educational attainment, or contributing uniquely to the understanding of the challenges of diabetes self-management and people’s engagement with the healthcare professionals and educational resources. A recent study has suggested that health literacy mediates the association between educational attainment and health behavior in people with diabetes.17 However, few studies have examined the relationship between health literacy and health outcomes across different socioeconomic groups. Thus, we sought to explore whether health literacy was associated with self-management and outcomes across different socioeconomic groups.
In addition, the majority of previous studies of health literacy and diabetes management have focused on people with type 2 diabetes; however, knowledge about health literacy and HbA1c among people with type 1 diabetes remains scarce and inconsistent. Therefore, we sought to investigate the association between each of the nine domains of the Health Literacy Questionnaire (HLQ) and HbA1c level in a large population of people with type 1 diabetes. We hypothesized that higher health literacy was independently associated with lower levels of HbA1c as a marker for HbA1c level and that this result would be consistent across groups with different levels of educational attainment.