What are the main pathways through which health literacy may impact people’s health status?
By OMARWALID NOORZADA
“Health literacy”, despite being a new concept to the health care community, has become center of the attention, due to its omnipresent impact on health. It is of interest not only to the medical field but also to the field of public health more generally.
Health literacy is postulated to be a more powerful predictor of health outcomes than social and economic status, education, gender, and age. People with poor health literacy have poorer health outcomes regardless of the disease in question. Low to moderate levels of health literacy have many repercussions on the individual and societal levels such as higher health care expenditure due to more prescriptions and treatment errors, higher rates of doctor visits and hospitalization; leading to increased costs mixed with an increased burden shared by health care providers and those who have to finance them. Similarly “people are more likely to skip necessary medical tests, end up in the emergency room more often, and have a harder time managing chronic diseases like diabetes or high blood pressure”, explain Rudd et al. The most vulnerable populations are the elderly, people with lower education status, minorities and persons with chronic diseases. “Nearly 9 out of 10 adults have difficulty using the everyday health information that is routinely available in our healthcare facilities, retail outlets, media and communities”, write Kutner et al.
The definition of health literacy has been evolving. WHO has defined health literacy as “the cognitive and social skills which determine the motivation and ability of individuals to gain access to, understand, and use information in ways that promote and maintain good health.” The American Medical Association (AMA) says “health literacy is a constellation of skills, including the ability to perform basic reading and numerical tasks required to function in the health care environment.” Finally, the Institute of Medicine (IOM) has defined health literacy as “the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions”.
On the top of that, many researchers in the past have limited health literacy to the knowledge, information and decisions taken within health care settings (medical literacy). In the last decade of the 20th century, Nutbeam put forward the broader concept of health literacy at three different levels: a “ three-tiered concept” that extended from “functional” (basic reading and writing skills to understand and follow simple health messages), “interactive” health literacy (more advanced skills to manage health in partnership with professionals) to “critical” health literacy that refers to the ability to critically analyze information, increase awareness and participate in action to address barriers with the aim of optimizing prevention and self-management of diseases and conditions. The triad of health literacy implies that it is not only the proximal (downstream) factors at the “micro level” that matter but also the distal (upstream) factors at the “macro level”, which are the social, economic and environmental determinants of health. In other words it means that health literacy is strongly associated with SES indicators, including educational class, race/ethnicity and age. It is therefore difficult to figure out the independent effect of health literacy on health status of population given that there is an intricate interaction with these factors.
Health literacy is also a type of incorporated cultural capital (non-monetary health resource), based on Pierre Bourdieu’s notion on forms of capital: capital is unequally distributed across educational classes and interacts with social and economic capital (monetary health resource). “Capital interplay” bridges the behavioral and structural determinants of health. This explains how behavioral transformations may result from cultural, economical and social capitals that lead to the alteration of the health status of people.
Evidence suggests that health literacy has gained importance globally not only in governments’ minds but also in international NGO’s and is labeled as an “access and equity issue” and “right of citizens.” Kickbusch et al. have exhorted European countries to ameliorate and enhance public health literacy through a set of recommendations devised for the sake of abating the health inequalities and building on the “health status” of individuals and group level.
On the other hand, the direct pathways between health literacy and health outcomes are nicely illustrated in the conceptual model produced by Paasche-Orlow & Wolf.
There are claims that people with poor health literacy have less understanding about their health (not understanding prevention and signs and symptoms of disease), have worse chronic illness control, have poorer physical and mental health functions (which might make the patient-provider interaction difficult and lead to miscommunication), receive less preventive care, but higher emergency department and hospital utilization. Likewise they might feel ashamed of their lower health literacy that might be exposed while interaction with health professionals. “Limited health literacy” occurs when people cannot find and use the health information and services they need. Besides it is found that minimal health literacy is associated with lower satisfaction, skepticism and negative thoughts about treatment and health providers.
Although scientific evidence from different studies has yielded a positive relationship between health literacy and health outcomes, the causal pathways are still not known. However, potential mechanisms have been explained.
For instance, a study showed that patients with higher health literacy had significantly lower viral loads and were significantly more likely to have an undetectable viral load than were those with lower literacy. Moreover, patients with lower health literacy were significantly more likely to have CD4 cell counts <300 cells/mm3 (300 being the threshold for immune system normality). Additionally, patients with lower health literacy were significantly more likely to have been hospitalized three or more times for HIV-related conditions compared with the higher literacy individuals.
Other studies have found that limited health literacy leads to undesirable health outcomes for other complex diseases. To give an example, a study conducted on patients who had Type 2 diabetes in two primary care clinics in San Francisco, California, showed that patients with inadequate health literacy were more likely than patients with adequate health literacy to have poor glycemic control. Furthermore, patients with inadequate health literacy had higher rates of retinopathy than patients with adequate health literacy.
Besides, inadequate health literacy paves the way for difficulties in reading and interpreting labels on prescription drug bottles, as Davis TC et al. found out: low literacy is significantly associated with more than three times greater likelihood of incorrect interpretation of drug warning labels. Likewise, poor medical adherence has also been associated with poor health consequences: a study on 145 HIV-positive individuals from Atlanta, Georgia on ART showed that individuals with lower health literacy were significantly less likely to have taken medications at adherence levels of 80%, 85%, and 90% of pills taken. Lower literacy was associated with poorer adherence over and above other factors included in the study such as years of education, HIV symptoms, emotional distress, internalized stigma, social support, and alcohol abuse.
The above-mentioned studies underline the association of health literacy and health status. It is safe to assume that there is a link between possessing adequate knowledge about health and taking the right decisions regarding health matters.
In a nutshell, as we began the third millennium the direct and indirect ways through which health literacy affects health status remain elusive. The miss match of health literacy through different pathways might affect all individuals and identifying those who are suffering from low health literacy has taken the form of a “hidden epidemic”, due to the fact that there is no single standard for screening people of low health literacy, screening being expensive and time consuming, and the problem of targeting all interventions at the individual level. Hence, some people are disproportionately affected – the elderly, immigrants, racial and ethnic minorities and those with limited education.
Health literacy is context-specific in terms of its acquisition and application, that is, individuals are not only affected by the health literacy of their own but also of those living around them (families, friends, neighbors and colleagues). Therefore, the most ideal and appropriate concept of health literacy would be when individual levels of knowledge and skills:
- enhance personal empowerment
- place greater emphasis on heath literacy outside of health care settings
- improve access and understanding of information to promote and maintain good health (physical, mental and social)
- build up on the understanding of conditions that determine health and know how to change them
- reduce distrust and miscommunication between patient-provider (having the potential to impact preventative health and reduce pressures on health systems).
Interactions between health literacy and health status can be either direct or indirect. A direct pathway would include factors that affect the health status directly, meaning that they are essential for a good health status. On the other hand, indirect pathways represent a complex interaction and relationship of different factors that are not the proximal cause of poor health but are nevertheless contributors to a low health status labeled as “cause of causes.” It is important to distinguish the different types of pathways and mechanisms so that interventions can be effective and contribute to a healthier living. These mechanisms include miscommunication, patient-provider distrust, lack of navigation skills, capital interplay, medication adherence, access, interpretation and proper usage of health related information, direct and indirect costs, unequal distribution of social determinants of health and so on. They all lead to delay in seeking care, unnecessary overutilization of health care services, reduced primary prevention, increased social and individual adverse outcome resulting to bad health status at individual and community level at last. Hence more research is required in order to unravel and fill the gaps regarding the exact ways in which health literacy alters the health status of people in the society.
“Health literacy” is relevant to individuals who may never become “patients” or deal directly with the health system, whereas “medical literacy” is not. Health literacy is a “resource for daily living in the settings where people live, learn, work, worship and play”, and “health status and learning are closely linked at all ages and stages of life”.
As new social, environmental and economic problems add up to the old ones such as globalization, climate change, global warning and the economic crisis, there is a dire need that all members of society, not merely individuals, understand how these distal determinants of health affect their health status so that they are able to identify and address them in the time to come. The WHO Regional Office for Europe has recently published a policy document that pinpoints the necessary actions needed to be taken at different levels: “to ensure better health communication through establishing health literacy guidelines; to create and strengthen health literacy– friendly settings; and to develop policies for health literacy at the local, national and international level.”
To sum up, health literacy ought to be the common 21st century currency held and shared by all the individuals in the community until we move towards the direction of a decreasingly unequal distribution between and within countries irrespective of race, ethnicity, sex, socioeconomic status, while being culturally and linguistically acceptable.
A healthier world is in reach as we contribute towards realizing the ideal of a health literate public.