How readable are Australian paediatric oral health education materials?

Dental caries in children is an international public health problem[1]. Despite improvements in oral health over the last 20 years, dental caries is identified as one of the most prevalent chronic diseases of childhood especially for those from a disadvantaged background[2‐4]. The most recent Child Dental Health Survey of Australia in 2007 reported that 46 percent of the 6-year-olds had one or more decayed, missing or filled primary tooth and 10 percent of those examined were found to have 10 primary teeth affected[5]. Data from the United Kingdom (UK) and the United States of America (USA) show a similar picture[6, 7]. If left untreated, childhood caries can lead to reduced growth, nutritional and sleep problems, problems with eating, speaking, and learning, as well as the potential to disrupt family life[1].

A history of childhood caries is the most reliable predictor of future caries development which presents a large financial burden for the local health services and individual families[8, 9]. It is therefore essential to prevent childhood caries before the subsequent need of resource intensive clinical interventions and treatments.

Parents are often the child’s first teachers and play a significant role in maintaining their child’s overall health by transferring health-related habits to their children. One possible solution to promote healthy habits in children is to motivate parents during the child’s early years of life as habits developed during the primary socialisation process are likely to be carried forward into adulthood[10‐12]. However, developing good dental habits during early childhood is a complex process and is largely dependent on a broad range of individual, family and community level factors[13].

The dental professional team, government health departments and industry partners play a role in educating parents to support developing good dental habits. In order for parents to implement preventive oral health routine for their children, they must have adequate functional oral health literacy i.e. a person’s ability to read and understand written oral health education materials[14]. Although there is evidence that patients generally prefer written information[15, 16], it is often noted that leaflets are poorly designed[17, 18]. For example, it was noted elsewhere that the reading skills of parents of paedatric patients were several grades lower than their reported highest level of education[19]. As a result some authors[14, 20, 21] have suggested that the value of health education literature may be compromised by an individuals’ literacy skills and that this may hinder his/her ability to obtain, understand and act upon the key health messages.

In 2006, the Adult Literacy and Life Skills Survey in Australia documented that 59 percent of the population aged between 15 and 74 years scored below a level of literacy regarded as optimal for health maintenance[22]. The Australian Bureau of Statistics (ABS) Report also noted that people with lower levels of health literacy often belong to one or more of the following categories: lower socioeconomic class, lower income and/or education, migrants from non-English-speaking countries and living farther from metropolitan cities[22]. It has also been concluded elsewhere that lower levels of health literacy is associated with higher use of expensive care, emergency services and increased rate of hospitalizations[23]. Further, a recent systematic review reviewed the impact of parental health literacy on child health outcomes and concluded that lower levels of parental literacy were associated with poor child health outcomes[24].

Despite the current research on general health literacy, very few studies have examined oral health literacy. Jackson introduced the scope of the problem of lower level of parental oral health literacy and child oral health outcomes and suggested several methods of improving communication between the dental professional team and the parents[25]. Studies conducted in the UK and the USA reported that public dental education materials were difficult to read for their respective population[26‐28]. However, to date none have investigated the readability of paediatric dental education materials in Australia. Therefore, the aim of this study was to examine the content and general readability of paediatric oral health education materials available in Australia.

We contacted Australian State and Territory Health Department’s; industry partners; and commercial organisations for all possible oral health education leaflets (n = 40) pertinent to paediatric oral health. Two were produced by the Australian Dental Association (ADA); six were from commercial organisations such as Colgate-Palmolive, Macleans and Oral B; and the majority were published by State/Territory Health Departments. The leaflets were appraised based on their textual framework, thoroughness, use of jargon terms and readability.

Educating parents on child oral health related issues is one of the most important steps during the primary socialisation process. Leaflets form an important link in the chain of communication between oral health professionals, the parents and the child. As noted in this study, although many paediatric oral health leaflets exist in Australia, they vary in content and readability. It was noted that leaflets that were adequate in terms of low literacy demand often had minimal information on child oral health. Conversely, the leaflets that had comprehensive information required higher literacy skills, which may be difficult for parents from disadvantaged backgrounds or those from linguistically diverse communities. Our results suggest that is likely that leaflets with simple messages and low literacy demand are read by more people compared to comprehensive leaflets.

The present study utilised three measures of readability assessment (FKGL, Fog, and SMOG) due to their simplicity and widespread use[32]. The grade levels calculated by FKGL were lower compared to Fog and SMOG, while the difference between Fog and SMOG were small (Figure 1). It is pertinent to note that these formulae are validated against the McCall- Crabs Passages[32]. These differences are noted because the FKGL predicts the grade level based on 75 percent comprehension, while the Fog and SMOG predict the grade level based on 90 percent and 100 percent comprehension respectively. Although other methods to assess the readability of education materials such as the SAM method (Suitability Assessment of Materials) are available[27], these were deemed inappropriate for this study as some leaflets contained less than 100 words.

The use of formula based readability assessment provided useful information on only one aspect of readability i.e. the level of education required to comprehend the leaflet. Other aspects such as font size, font colour, the use of bold and italics text, use of bulleted text; use of instructional pictures; use of simplified sentences, and sentence length which contribute to the overall readability[28, 34, 35] are not assessed by the readability indices. However, in this study, some of these aspects such as the use of bold and bullet text and the use of pictures were assessed. It has also been noted elsewhere that readability formulae should only be used as a guide to assess the reading difficulty of a text as they do not take into account other factors that can influence comprehension[36] such as the use of active and passive verbs, the way the information is organised on a page and the reader’s motivation and level of prior knowledge[37]. Blinkhorn and Verity[38] noted that dental professionals use professional terminology that may be incomprehensible to a common person and that readability formulae may therefore underestimate the difficulty of a text.

The content analyses of Australian leaflets revealed the prevalence of conflicting health education messages as noted by other researchers[31]. It is noteworthy that research in experimental psychology and marketing highlights that humans have a cognitive preference for picture-based, rather than text-based information: the so-called picture superiority effect[39, 40]. Although majority of the leaflets had relevant pictures, it was surprising to note that some leaflets did not have photographs to convey important messages to parents of young children such as how to brush the child’s teeth and the amount of toothpaste to be used. Similar to other studies[27, 28, 31], the present study identified aspects of oral hygiene instruction such as how to brush teeth that were not covered by majority of the leaflets. Pictures have been a useful tool in health sciences to covey health messages and would be useful for Australian dental professionals to convey the correct information about toothpaste use and other aspects of oral hygiene using illustrations as it is reported that patients retain more health information to visual presentations[40, 41].

Although there is no gold standard tool to assess a patient’s oral health literacy at this stage, several instruments are being developed as research in this aspect of oral health is increasing relatively[21]. It is now noted that oral health literacy is an important link between health behaviours and oral health outcomes[20]. Although there is evidence that improving patients’ literacy can improve health outcomes[42], it is still unclear if improving patient education materials can lead to better health outcomes[43]. However, it is pertinent to note that producers of dental health education materials should be aware of several parameters when designing leaflets. These include general readability of leaflets; coverage of important health topics with simple and consistent messages; the use of pictures to convey health messages; and avoiding the use of jargon terms. Health education leaflets that are clear, concise, consistent and thorough are a simple way to bridge the communication gap between the oral health professional, parent and the child.

The present study has several limitations; although several criteria were used to evaluate the readability of the leaflets, there were some aspects of the general readability that were not assessed. These include the use of bright colours, use of active and passive verbs, the use of italics to emphasize information, and the advantageous use of white space[34]. Second, the list of dental jargon terms noted in this study were subjective. However, it is important to note that other authors have noted similar words in their studies[28, 31]. Thirdly, although all possible Australian sources were searched to collect leaflets, it may be possible that some paediatric oral health leaflets were inadvertently missed. Finally, the current evaluation does not include the opinion of the parents which will be prudent to re-design of the leaflets in future.

Australian paediatric oral health education materials are readily available, yet their quality and readability vary widely. Leaflets produced by local Health Departments are more readable compared to commercial and industry counterparts. The results show that a large number of paediatric dental leaflets may be difficult to read for disadvantaged populations in Australia. A redesign of these leaflets while taking literacy into consideration is suggested.