Effectiveness of using picture-based health education for people with low health literacy: An integrative review

Abstract Background: Level of health literacy affects health status. The purpose of this study was to examine and evaluate studies related to picture-based health education materials for people with low health literacy. Methods: Articles from 2001 through October 2015 were searched in the PubMed, CINAHL, and ERIC databases on the web, followed by manual searches of the references in those articles. Results: Of the 11 studies that met the inclusion criteria for this review, 10 showed a positive effect of increasing the health learning abilities of people with low health literacy using picture-based health education. Medication adherence was targeted most often. The majority of the studies measured health literacy using the Short Test of Functional Health Literacy in Adults, but the health literacy measurements in picture-based health education were nonetheless inconsistent. Discussion: Use of picture-based health education for people with low health literacy was limited. However, the majority of the studies did indicate a positive effect on learning.


Introduction
Health literacy has been defined 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" (Nielsen-Bohlman, NetLibrary, & Institute of Medicine (US) Committee on Health People with low health literacy have many difficulties in managing their health problems (Arcia, Bales, & William Brown, 2013;Paasche-Orlow, Parker, Gazmararian, Nielsen-Bohlman, & Rudd, 2005) and as a result experience longer hospitalizations and more frequent use of emergency care. This may be due in part to difficulty accessing the correct medication, and understand labels and health messages (Arcia et al., 2013;Berkman, Sheridan, Donahue, Halpern, & Crotty, 2011). Those with limited health literacy are therefore more likely to become ill than those with higher health literacy (Garcia-Retamero, Okan, & Cokely, 2012).
Health education materials, however, are not always appropriately written for those with low health literacy, and the materials that do take low health literacy into account are limited. Health education materials are often written for a 10th-grade reading level (Davis et al., 1993;Doak, Doak, Friedell, & Meade, 1998) but the reading ability of people with low health literacy can be below the 5th-grade level (Kirsch & Educational Testing Service, & National Center for Education Statistics, 1993). One way to address this health knowledge gap is to use picture-based educational materials.
The Mayer's cognitive theory of multimedia learning (CTML) insisted three principles: (1) people process information through auditory and visual channels, (2) each channel has a limited amount of memory, and (3) learning consists of actively filtering and sorting information (Mayer & Ebooks Corporation, 2009). Given these principles, multimedia, which may be defined as "the combination of text and pictures," should help improve an individual's capacity to learn (Sorden, 2012), and the CTML is indeed based on the idea that learners can improve their learning abilities when they are presented with pictures as well as words (Choi, 2015;Mayer & Ebooks Corporation, 2009). Thus, the combination of pictures and words increases learning effectiveness (Mayer, 1947(Mayer, /2014Sorden, 2012).
Following the Mayer's CTML theory, pictographs may increase the effectiveness of educational materials for those who have low literacy (Garcia-Retamero et al., 2012) especially for complex health information (Austin, Matlack, Dunn, Kesler, & Brown, 1995;Delp & Jones, 1996). However, pictographs encompass many different picture-based educational materials in a diverse health education fields, such as simple black and white line drawings, pictures, and simple drawings with simple text. The purpose of this integrative review is to synthesize studies associated with pictographic education designed for people with low health literacy, describe the characteristics of pictographs use, assess the tools used to measure health literacy in picture-based health education studies, and integrating the effectiveness of picture-based health education for people with low health literacy.

Search strategy
For this study, we systematically reviewed articles found with two main search methods: (1) electronic searches using key words in library databases, and (2) subsequent manual searches for related references. On the Internet, we searched three databases: PubMed, the Cumulative Index of Nursing and Allied Health Literature (CINAHL), and the Education Resources Information Center (ERIC). Search terms were as follows: photo novella, education, cartoon, webtoon, pictograph, pictogram, illustration, picture, visualization, health, nonliterate, and literacy. The research on picturebased materials for health education is limited, so we did not limit the time period for the review. Through an ancestry search, additional research studies were identified by searching reference lists that had inclusion criteria and purposes that were related to those of this review. The search strategy and data extraction are illustrated in Figure 1.

Inclusion and exclusion criteria
This study was guided by inclusion and exclusion criteria: (1) English-based studies, (2) studies related to low health literacy, (3) studies use picture-based health education, (4) study participants are adults (over 18 years old), (5) studies are not reviews or meta-analyses, and (6) studies are not dental related.

Data extraction
Initially, the web-based search identified 70 articles in PubMed, CINAHL, and ERIC. Manual search of the references in those articles found an additional 22 articles, for a total of 92. After screening the 92 articles by title, key words, and abstract, 44 articles were excluded because they were editorials or presented only abstracts, were duplicates, were not written in English, applied to dental health of youth, were unrelated to health care, or did not consider participants' levels of health literacy. Full texts of the remaining 48 articles were then read. Review of those 48 articles led to exclusion of 20 articles from the web-based search because (1) the participants were not adults (over the age of 18), or (2) the articles were reviews or meta-analyses. A total of 17 articles from the manual search were also excluded after applying the same inclusion and exclusion criteria.

Studies' characteristics
Five descriptive studies (Choi, 2011(Choi, , 2012(Choi, , 2013DeWalt et al., 2004;Kripalani et al., 2007) consisted of picture-based educational tool development and evaluations using interviews to determine whether a pictographic health education approach was effective or not for people with low health literacy

Study designs and picture-based development fields
There were four types of study designs: tool development (n = 4), tool development and evaluation by experts (n = 1), tool development and evaluation by patients (n = 3), and tool evaluation only (n = 7) (see Table 3). The health conditions focused upon in the picture-based development were medication adherence (n = 5), hip replacement surgery (n = 3), breast healthcare (n = 1), heart failure (n = 1), and human immunodeficiency virus (HIV; n = 1).

Characteristics of pictographs
Studies used pictographs for low health literacy people. The majority of the studies used simple black and white pictographs (n = 4). Five studies used pictographs to assist patients with their medications (Chuang et al., 2010;Dowse & Ehlers, 2001Kripalani et al., 2007;Mansoor & Dowse, 2003). Most studies used pictographs were conducted in the US (n = 7). Ten of 11 articles were the positive effect of increase understanding health education materials.

Health literacy assessment tools
Four different tools were used to assess health literacy: the Test of Functional Health Literacy in Adults (TOFHLA; n = 1), the Short Test of Functional Health Literacy in Adults (S-TOFHLA; n = 4), the Rapid Estimate of Adult Literacy in Medicine (REALM; n = 2), and the Short Literacy Test (n = 1), along with education level (n = 5).

Study Research design N References*
Descriptive Cross-sectional 6 Choi (2011Choi ( , 2012Choi ( , 2013, Chuang et al. (2010), DeWalt et al. (2004, Kripalani et al. (2007) Intervention RCT 5 Choi (2015), Dowse and Ehlers (2005), Kalichman et al. (2013), Kripalani et al. (2007), Mansoor and Dowse (2003) Pre The reading levels in the studies that used the S-TOFHLA were reported as marginal or inadequate (S-TOFHLA ≤ 22) in the majority of the studies. If the researchers used years of education, the variables were dichotomized, using the cut off of elementary, less than middle school, or less than high school.

Relationship between pictography and health education effect
All of the articles described the effectiveness of using pictographs for health education for those with low health literacy. Studies measured effectiveness by using interviews, paper-based self-reports, and questionnaire surveys. Pictography made low health literacy people easy to understand. Ten of the 11 articles (Choi, 2011(Choi, , 2012(Choi, , 2013(Choi, , 2015Chuang et al., 2010;DeWalt et al., 2004;Dowse & Ehlers, 2001Kripalani et al., 2007;Mansoor & Dowse, 2003) found a positive effect of Table 3

. The analysis of study components
Notes: TOFHLA-test of functional health literacy in adults; S-TOFHLA-short test.
*References include duplicated studies. **Number of participants studied, whether participants were experts or patients.

Study design
Tool development and evaluation by experts pictographic educational materials on health self-management, regardless of race/ethnicity and country of origin. However, in Kalichman et al. (2013) the pictograph and adherence to counseling did not improve outcomes in persons with low literacy, though it was effective in persons with moderate health literacy. They surmised that patients with low literacy will need more intense interventions than a brief counseling session to overcome this barrier.

Discussion
The 11 articles in this integrative review focused primarily on health literacy measurements, specific health conditions, and the picture-based format of health education materials for people with low health literacy. The review suggests several key findings.
First, communication about health-related subjects with those who have low health literacy is challenging (Arcia et al., 2013). Pictographic representation, however, is beneficial for comprehension and communication in health care (Arcia et al., 2013). Nevertheless, the areas of healthcare that currently use picture-based education for people with low health literacy are limited. In addition, although limited health literacy is affected by age, no studies have focused on the use of pictographic education for the aging population. There is need for more diverse health-related research studies using pictography-based health education materials for elderly.
Currently there are no standard tools for the assessment of health literacy, thus it is difficult to compare levels of health literacy across the studies reviewed here (Berkman et al., 2011). Several of the studies used the dichotomous variable of years of education, but that is not always an appropriate measurement. Health literacy measurements may focus on assessing reading, comprehension, and numeracy (Jordan et al., 2013), but years of education do not provide an accurate measurement of those components. To accurately measure health literacy, future researchers will need more meaningful and consistent health literacy assessment tools.
Finally, picture-based educational materials significantly improved participants' understanding of their health. Most of the studies reported positive results for using pictographic educational materials in healthcare. All 11 of the articles demonstrated the effectiveness of pictographic health education materials increasing patients' learning abilities in different countries, and one article directly pointed out that pictographic health education is effective regardless of race/ethnicity (Choi, 2012). However, one article of HIV education indicated that using picture-based materials did not result in any difference, because people with low health literacy may need more intensive approaches to improving their health. Overall, most of the health education materials currently available are not appropriate for people with a low health literacy level, so improved materials are highly needed.
This integrative review determined what health focus areas were addressed by picture-based health education, the trends that exist in picture-based health education for people with low health literacy, the best health literacy measurements for people with low health literacy, and the effectiveness of picture-based health education for improving the health status of people with low health literacy.

Conclusions
In the US, substantial numbers of adults find it difficult to understand data about their health (Arcia et al., 2013). People's levels of health literacy affect their health and their health management in many ways (U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion, 2010). Low health literacy can lead to greater chances of missing crucial information and therefore causes higher error rates in patients' judgments and decisions about their illnesses (Garcia-Retamero et al., 2012). This results in a direct influence on the status of their illness (Garcia-Retamero et al., 2012). There is a positive relationship between understanding one's health data and improving one's health self-management (Arcia et al., 2013). However, despite attempts to address patients' low health literacy, the majority of materials provided to people with low health literacy are written by people with a high reading level (Badarudeen & Sabharwal, 2008;Goodfellow, Trachimowicz, & Steele, 2008;Helitzer, Hollis, Cotner, & Oestreicher, 2009;Hill-Briggs & Smith, 2008;U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion, 2010) and healthcare experts have followed only some of the recommendations made for working with people who have low health literacy (Schwartzberg, Cowett, VanGeest, & Wolf, 2007;U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion, 2010). In this integrative review, we sought to explore which areas of healthcare have used picture-based health education for those with low health literacy and, ultimately, how effective those materials have been. So far, the areas of healthcare using picture-based health education for people with low health literacy have been limited, although the majority of studies indicated a positive effect on learning ability.

Strengths and limitations
Most studies indicated that using picture-based health education materials for people with low health literacy had a positive effect on health care. But few picture-based health education studies met the inclusion criteria for this integrated review. In addition, the studies were reviewed by only two authors, which may have led to bias; however, the two authors did review the studies three separate times and also subjected their process to review by peer colleagues. There were not many studies that have been done so far; any generalizability of the findings might be limited. Moreover, there were few intervention studies and few participants for assessing the effectiveness of pictographic health care education. In the future, more intervention studies and greater numbers of participants would enable generalizability. In addition, most of the pictographic health care education focused on medication; few studies addressed other healthcare areas. In the future, more research needs to be done on picture-based education in additional areas of healthcare and on a wider range of diseases in order to evaluate its effectiveness.

Practice implications
In order to address low health literacy needs, healthcare professionals should evaluate their current patient education for reading level and low-literacy acceptability. Reading levels can be assessed using the health measurements tools such as S-TOFHLA, and REALM. Patient education handouts should be on a reading level below 5th-grade level (Kirsch & Educational Testing Service, & National Center for Education Statistics, 1993). If there is a lack patient education materials tailored for low health literacy, healthcare professionals can create patient education material using picture-based information. Pictures should be simple, clear, and culturally tailored for easy to understand. Appropriate picture-based health education materials would make it easier for such people to understand health information, as opposed to text-based health education materials alone.