Canadian Expert Panel on Health Literacy [1] and Calgary Charter on Health Literacy [2] define Health literacy (HL) as a person's ability to access, navigate, and find health information in different formats, and to be able to use personal capacity and skills to understand, evaluate, communicate, and use the obtained information to make informed decisions for their health. The five core HL domains captured amongst the literature are access, communicate, evaluate, understand, and use health information [1, 3]. Historically, researchers have also considered numeracy to be a HL skill; however, since numeracy is a variable applicable to all core HL domains, it should be assessed across the domains rather than independently [4–6].
Several reports from various local and global organizations indicate that the prevalence of low HL is a significant and growing public health concern [7, 8, 9, 10]. Such an issue has the potential to widen existing health inequities in acquiring care services and health information, especially among disadvantaged populations including older adults [11, 12], minority groups, and individuals of low socio-economic status, as reported by numerous studies [13–15]. Individuals with low HL face barriers to adequately accessing health services, and may encounter challenges when communicating with health care providers or making informed health decisions, both of which are crucial elements of disease self-management practices [16, 17, 18].
Aging populations may lead to an increased prevalence of chronic conditions worldwide and the problems associated with low HL may be aggravated by this demographic transition [19]. Studies have demonstrated that many adults with chronic diseases, including chronic airway disease (CAD), have difficulty comprehending their treatment process, mainly due to a lack of skills necessary to engage in optimal self-management practices [20, 21]. It has also been reported that inadequate HL is associated with increased rates of unnecessary hospitalization and emergency department visits [22, 23], poor medication adherence [24, 25], lower quality of life [26, 27], and increased mortality [28, 29]. These studies concluded that empowering patients with HL and self-confidence skills could enhance their self-efficacy in controlling disease symptoms and managing their disease condition, which may improve health outcomes.
Various studies have reported the link between HL and CAD outcomes [30–34]. Most published HL studies are descriptive or cross-sectional, and primarily establish the association between HL and health status; however, these studies do not establish the long-term effectiveness of HL-based interventions on health outcomes, mainly because they do not apply proper measurement tools [13, 33, 35–37]. From a methodological point of view, HL measurement tools reported in the literature have received criticism for their inability to incorporate the full spectrum of key factors influencing an individual’s HL skills [13, 38]. In addition, most existing HL tools for CAD management fail to encompass all 5 essential HL domains and numeracy comprehensively [17, 39, 40], as well, the models they applied do not consider the impact of internal and external factors on the attainment of HL skills in their conceptual framework. These methodological deficiencies may limit the understanding of essential factors that may influence a patient’s engagement in self-management practices.
Pleasant et al (2011) [41] and Sørensen et al (2012) [3] summarized numerous debates concerning issues with existing HL measurement tools, and indicated that there was a lack of true theoretical frameworks with added behavioural components that comprehensively explain the link between HL and health outcomes. Similar debate has been called for developing a comprehensive HL measurement tool for chronic disease management, that not only enables researchers and clinicians to adequately assess HL skills, but also informs the need for practical interventions aiming to empower patients to effectively self-manage their chronic condition(s) [13, 42, 43]. The call was acknowledged by many researchers globally and there have been continued efforts to: 1) clarify how HL is conceptualized at different levels of practice [44]; 2) further demonstrate the causal link between HL and disease self-management [45, 46]; and 3) integrate personal attributes and social support into HL interventions to facilitate patient engagement in the disease management process [47, 48]. These studies and other research shown there is a paucity of HL-related interventions that consider the influence of personal, social, and systemic factors on disease self-management practices and the decision-making process [49–53].
The multidisciplinary field of HL is rapidly evolving and expanding [52, 54], therefore, there is a need to develop and apply appropriate framework to measure comprehensively the concepts of HL. Several models have been reported in the literature describing HL as a multidimensional construct that improves an individual’s skills related to accessing, understanding and using health information to make informed decisions about one’s health [55, 56]. For instance, McCormack et al. [57] developed a model that presents HL as an individual-level attribute that is affected by predisposing factors or socio-environmental aspects of the target population (e.g., culture and beliefs). Other models focus merely on mediator elements (factors that influence a relationship) between HL and health outcomes, and how the model can be used as a screening tool [47, 54, 58]. Therefore, there have been significant challenges in applying the existing models in clinical practice, as their approaches are primarily theoretical (research-based) and lack clinical significance and applicability. According to our knowledge, no conceptual model has been reported in the literature that conceptualizes HL as a preventive measure and empowerment tool that can enable an individual to consciously modify their health behaviours. There is also a lack of reported involvement of community members during the design and evaluation stages of such models, as well as failure to consider the full spectrum of factors intrinsic to an individual (e.g., beliefs, worldviews, perceptions, and practices). These intrinsic factors may influence decision-making, navigation of health system complexities, and the attainment of the requisite skills for successfully maintaining health throughout different stages of one's life. Institute of Medicine 2004 report concluded to enhance our understanding of factors that may contribute to a person’s HL skills, and how these skills can influence a patient’s empowerment and level of self-efficacy to engage in disease self-management practices [46]. Therefore, a clear and grounded conceptual HL model for CAD management is imperative, yet absent from the literature.
Purpose
The purpose of this article is to summarize the process of developing our Chronic Airway Disease Management and Health Literacy (CADMaHL) Model (Fig. 1. Multistage study process), including a conceptual framework of HL (Fig. 2. Conceptual model for measuring health literacy (HL) in CAD management). The CADMaHL model was developed with enhanced consideration for current methodological deficiencies of existing HL tools reported in the literature. We applied insights shared by participants in different study stages related to the interaction of personal attributes, external barriers and facilitators, and an individual’s capabilities to apply HL skills in decision-making process, as well how self-management practices may be affected by HL skills in the model. The model was used to the development of a functional-based HL measurement tool for asthma and COPD management among adult patients, as explained below. The anticipation is that the model may also guide the development of intervention studies to address the longitudinal influence of HL skills on CAD outcomes. In this article, we included information on how the CADMaHL model can be applied to guide future research, evaluation, and interventions on CAD management.