Age-related macular degeneration (AMD) is a chronic eye condition that leads to permanent vision loss in the central visual field. AMD is a leading cause of vision loss for people age 50 and older.1 An estimated 1.8 million people are affected by AMD in the United States (U.S.) alone.2 Difficulty reading is one of the most common complaints from patients seeking low vision rehabilitation services.3,4 Central vision loss makes reading challenging and inefficient. Additional time, attention and effort are needed to process and understand written text.5 Poorer reading performance may be due to decreased acuity and contrast sensitivity in the peripheral visual field, and factors associated with the size and style of font.6 In low vision rehabilitation, techniques to increase reading performance are often addressed. Adaptations may include use of optical devices such as magnifiers and closed-circuit televisions (CCTVs), and eccentric viewing training which is learning to use the undamaged area of one’s vision. These interventions improve access to text; however, they do not increase processing or understanding of complex written information such as patient education materials (PEMs). To promote health literacy, the demands of written text must match the literacy capacities of the reader.
Health literacy is defined as the degree to which individuals have the capacity to obtain, cognitively process and understand health information to make informed health-related decisions.7 Health literacy is demonstrated through skills in basic literacy when reading and understanding health information. Low health literacy is a significant problem in the U.S.8 According to the American Medical Association (AMA), over one-third of American adults, approximately 89 million people, have inadequate health literacy.9 Health literacy is the single best predictor of health outcomes.10,9
Readability and Suitability
According to Legge, there are two reasons why reading comprehension may be poorer in people with low vision.11 First, slower reading speed makes it difficult to maintain attention on text and integrate meaning across words and phrases. Second, the increased demands of decoding (i.e., translating print into words) and poorer quality of visual input may limit understanding. The readability and suitability of reading materials are additional factors that may impact reading performance in people with AMD. Readability is a quantitative assessment of the reading skills required to easily comprehend written material.10 Readability is calculated by applying a mathematical formula to a sample passage of written text. A grade level (i.e., number of years of education needed to comprehend written text) is produced based on the number of syllables, words and sentences. Several formulas are used to assess readability; however, there is no consensus as to which formula is best to assess the readability of PEMs. The suitability (i.e., appropriateness) of written information is another important factor impacting comprehension of written health information.12 For people with AMD, factors related to the layout and design of written information may support, or limit, comprehension of PEMs.11
In 2016, the Program for the International Assessment of Adult Competencies (PIAAC) published the most current indicator of basic skills in literacy, numeracy and problem solving skills of American adults.13 The PIAAC defines literacy as the ability to understand, evaluate, use and engage with written texts to participate in society, to achieve one’s goals and to develop one’s knowledge and potential. Findings from the survey indicated only 12% of American adults had proficient literacy skills. These results matched findings from the 2003 National Assessment of Adult Literacy (NAAL) survey which also found 12% of adult Americans had proficient health literacy skills to fully participate in the self-management of their own health.14 According to the Centers for Disease Control and Prevention, people with low literacy are more likely to report poor health outcomes.15
Comprehension of written health information is influenced by several factors including the ability to read text, locate and use written information in documents, and to use numbers embedded in print materials.16 According to the Pfizer Principles for Clear Health Communication, health outcomes are impacted by low health literacy in two ways: (1) a mismatch between reading abilities and the reading level of written health information; and (2) lack of health-related information that is easy to understand.8 Existing research indicates the impact of vision loss on health outcomes is often underestimated by health care providers.17,18 Health care providers who provide written PEMs must recognize how poor reading proficiency creates barriers to functional health literacy.19,20
The Center for Studying Health System Change reports 75% of physicians provide written PEMs on a routine basis.21 Existing research has identified a discrepancy between PEM readability and the average American adult’s capacity to comprehend written health-related information.10,22,23 Most PEMs are written at, or above, the tenth grade reading level and include written information too advanced for most patients to understand.24,25 On average, American adults read between the eighth and ninth grade level.14 The gap is even wider for older adults. According to the United States Government Accountability Office, the average Medicare recipient reads at, or below, the fifth grade reading level.26 The barriers to reading created by central vision loss put older adults with AMD at greater risk for low health literacy.27,14 To reach the needs of the largest range of adults, the AMA recommends health-related patient information be written below the sixth grade reading level.9 For people with low literacy skills, the National Institutes of Health (NIH) Clear Communication Campaign suggests writing between the third and sixth grade reading level.28
The internet has become the most widely accessible source of PEMs.29,30 A study by the Pew Internet and American Life Project found that 80% of American adults who use the internet have searched for online health information.31 Although it has become easier to access PEMs online, most American adults are unable to process or understand the technical information within them to inform health-related decision making.29 Determining whether existing PEMs meet the recommended guidelines for readability and suitability is a necessary first step for promoting health literacy and patient outcomes. This purpose of this study was to assess the general readability and suitability of online PEMs designed for people with AMD. This research is needed to determine if existing online PEMs are appropriate (i.e., readable and suitable) for this population, who is at greater risk for low health literacy.27,14
Gaps in the Literature
Existing research has explored the readability of PEMs across a variety of health conditions and subspecialties.10,32-35,22,23 A major gap in the literature exists surrounding treating people with AMD as a unique group under the larger umbrella of low vision.36 A handful of studies have explored the readability of online PEMs for a range of different ophthalmic diagnoses.37-40 None of these studies have explored the readability of PEMs designed for people with AMD. The suitability (i.e., appropriateness) of PEMs is also important when determining the fit between written health-related information and the reading capacities of a target population. To date, this is the first study to focus solely on the readability and suitability of online PEMs designed for people with AMD. This study is needed to fuel future research and develop population-specific PEMs that meet the unique learning needs of this population.
The purpose of this study is to determine the general readability and suitability of online PEMs designed for people with AMD. Furthermore, this study aims to identify the percentage of online PEMs that achieve the national guidelines for readability level (≤ sixth grade) and the recommended suitability score (≥ 70%). The researchers hypothesize that the majority of online PEMs designed for people with AMD will be written at grade levels above the recommended readability level, and below the recommended suitability score. To date, this is the first study to assess the readability and suitability of online PEMs designed specifically for people with AMD.