Health literacy is the ability to access, understand, appraise, and apply health information . Appraisal is the ability to evaluate information, and application refers to the ability to make informed decisions. Health literacy can help people become more empowered in relation to health care, disease prevention, and health promotion. The European Health Literacy Survey Questionnaire  has been used around the world  and in Japan [4,5,6,7,8,9,10,11,12] to measure comprehensive health literacy. Health literacy in Japan is associated with the following: health status and health behaviors in the general population [4,5,6,7]; social activity, exercise habits, and quality of life in patients [8, 9]; and a lower risk of atherosclerosis and lower frailty in elderly people [10,11,12].
In 2015, however, it was reported that comprehensive health literacy scores in Japan were lower than in Europe  and similar to the health literacy scores in six other Asian countries . A comparison of health literacy in Europe and Japan showed that a higher percentage of Japanese respondents rated as “difficult” items related to evaluating information and decision-making. Health literacy is ultimately about the ability to make informed decisions and requires the identification of quality information.
One reason for Japan’s low health literacy is the lack of reliable, easy-to-understand public websites and absence of a standard information source that people can access to obtain information rapidly. One report comparing the quality of cancer information on the Internet in the United States and Japan found that US information was better because it was mainly provided by non-profit organizations and public institutions . Another study in Japan found that among websites offering information about cancer treatment, the proportion of ones providing harmful information was much greater than the percentage of ones offering reliable information . In Japan, there is no reliable and comprehensive website comparable to MedlinePlus (US National Library of Medicine): Japan has neither a national institute of health nor a national library of medicine. Further, few Japanese use English on a daily basis; Internet use is predominantly in Japanese, which may limit the use of useful information in English more than in Europe.
The most common health information resources for Japanese people are television and radio (77.5%), the Internet (74.6%), and newspapers (60.0%); these resources were found to be trusted by 70.5%, 55.6%, and 76.2% of respondents, respectively . This high level of trust in mass media (such as newspapers and television) and low trust in the Internet is a characteristic of Japan that is not limited to health information. According to the World Values Survey, trust in newspapers and television is approximately 60%–70% in Japan compared with around 10%–40% in Western countries . However, another survey showed that trust in the Internet was lowest in Japan (51%) compared with 74% overall among the 25 countries and regions surveyed . Information access is changing, and many people now independently search for reliable information using the Internet. However, perhaps because it is difficult to obtain such information from the Internet, Japanese tend to rely on information from the mass media, which are less reliable than in other countries. This pattern may hinder Japanese from evaluating information for themselves and making decisions based on such information.
It is also possible that the type of education provided in Japan (from childhood onward) affects the development of information-evaluation abilities. Although Japanese are able to obtain and understand information, they are less able to evaluate it or make decisions; this is because Japanese education does not aim to develop those abilities. Only in the last few years has the ability to evaluate information and make decisions been included as a major pillar in the national curriculum guidelines for elementary through high school .
There are clear cultural differences in decision-making and the environment that enables it. In a comparison of Japanese and Australian university students, Japanese expressed lower self-esteem in decision-making, higher stress in decision-making, and the tendency to make decisions impatiently and incorrectly without considering other options; alternatively, they avoided decision-making rather than thinking a problem through and deciding for themselves . Similarly, in a study comparing university students in Japan, Australia, the United States, New Zealand, Hong Kong, and Taiwan, Japanese had the lowest self-esteem regarding decision-making and tended to be the most avoidant and impulsive . It has been pointed out that this may reflect a difference between Western culture (which promotes individual decision-making) and Japanese culture (which values group harmony). Further, a study comparing the decision-making styles of business leaders in Japan, the United States, and China found that in Japan gathering data and carefully analyzing many options was the least common style; focusing on intuition and relationships rather than data was the most common approach .
Similarly, regarding cultural aspects, it has been observed that Japanese have low self-esteem compared with North Americans . One study reported that in contrast to North Americans’ motivations to identify what is good in themselves, Japanese appear more motivated to find areas of insufficiency . However, further research is needed: there may be differences between North America and Europe even though in some areas there are few differences between those two regions.
The ability to make decisions may also be affected by whether or not there is freedom of choice. The World Values Survey contains the item “Please use the scale to indicate how much freedom of choice and control you feel you have over the way your life turns out,” which respondents rate on a scale of 1–10. In terms of average score on this item, Japan scored 81st among 83 countries and regions . This may indicate that Japanese feel they have insufficient options, insufficient information to make a decision, or lack the skills to make an informed decision.
It is necessary to examine the information-evaluation and decision-making skills that are needed to make informed decisions. Many university library websites worldwide have long published methods for evaluating information resources and websites. These methods involve tests and guidelines for judging the quality of information sources. Some of the most widely used are the following: CRAP (currency, reliability, authority, and purpose) , developed by a university librarian, which is a helpful tool when trying to decide if a website is a credible, valid source; and CRAAP (currency, relevance, authority, accuracy, and purpose) tests , which is widely used as a teaching tool for college students learning how to evaluate Internet resources. Similarly developed as a checklist for students, there are five criteria known as AAOCC (accuracy, authority, objectivity, currency, and coverage) [27,28,29], which include and are very similar to the criteria of CRAP and CRAAP.
The five AAOCC criteria can be defined as follows. Accuracy (or reliability) is whether the information is reliable, whether it can be verified by other sources, and whether it is clear what the original sources are and whether they contain sufficient evidence. Authority means that the identity and qualifications of the author or person providing the information are clear. Objectivity (or purpose) refers to whether the information is free from bias, why it is provided, and whether it is biased for advertising or commercial purposes. Currency signifies that the accuracy of the information source depends on when the information was created and how often it is updated. It is true that many older studies are still valid today; however, it is important to have current details about when the information was provided (such as when it was published or posted) so it is possible to confirm whether it is still accurate and has not been recently adjusted. Coverage (or relevance) is the extent to which the information addresses what the user wants to know, whether it is broad in scope or specialized, and how it differs from other information. To determine this, it is necessary to compare the information with other sources and clarify the differences, rather than making a judgment based on the original information alone. Thus, it is important that people develop the skills to identify and confirm these five criteria so that information can be properly evaluated and reliable information used.
Different people make decisions in different ways. Many studies have examined the psychology of decision-making styles; several measurement scales have emerged [30, 31]. Two major decision-making styles have been identified: the rational and intuitive styles. Consistent with previous studies, Hamilton et al. defined the characteristics of the rational style as a thorough search for information and a systematic evaluation of all choices and potential alternatives; they described the characteristics of the intuitive style as applying quick decision-making that is primarily based on hunches and feelings . The rational style scale includes evaluating information (such as thorough information gathering and investigating facts) and carefully considering pros and cons, or benefits and risks, to explore all options and evaluate alternatives. A rational style is needed for informed decision-making, which is the process of evaluating information (e.g., evidence and data) and options.
In the fields of business and health, individuals are required frequently to make decisions. In these areas, decision-making is a process: better decision-making demands the steps of generating options, comparing the options’ pros and cons, and then making a decision .
Decision-making has become integral to the research and practice of informed and shared decision-making (SDM) in the field of health . According to one systematic review of SDM, its essential elements are presentation of options, discussion of pros and cons, and patient values and preferences . This approach reflects the critical role in evidence-based medicine of patients’ values and preferences in decision-making . Similarly, patient-centered care takes into account the preferences, needs, and values of each patient; it ensures that the patient’s values guide all clinical decisions . Evidence-based medicine is an essential prerequisite of SDM ; Barry and Edgman-Levitan note that SDM is the pinnacle of patient-centered care .
A US national study to assess SDM developed a scale to assess four fundamental aspects (discussion of options, pros, cons, and preferences) that reflect the widely accepted definition of SDM [39, 40]. According to the Ottawa Decision Support Framework (a theory of decisional support for difficult decisions), the quality of decision-making requires that choices be made based on what is most important among the pros and cons of options . Decision aids (DAs) are tools that support decision-making; they help people determine the pros and cons of options as well as identify their importance. Such an approach leads to effective decision-making: it amounts to recognizing that the decision is informed, value based, likely to be implemented, and will probably lead to satisfaction with the decision . Recent research indicates that SDM and DA play an important role in decision-making in Japan [43,44,45,46].
The perceived difficulty of evaluating information and making decisions as health-related tasks has been included in scales measuring health literacy applied in studies comparing Europe and Asia [2, 4, 13]. The studies have assessed the ease for people to evaluate information and make decisions; however, they have not examined how the subjects did so. For individuals to assess health information, they may require specific skills for judging the reliability of diverse information using evaluation criteria. Furthermore, even if individuals possess reliable information to deal effectively with health issues, they need specific skills for implementing rational decision-making; that involves obtaining sufficient options, understanding pros and cons, and selecting the best alternative according to their values. Clarifying the association between health literacy and specific skills to evaluate information and make decisions (not necessarily confined to health information) would inform efforts to improve health literacy.
Accordingly, the objectives of the present study were to investigate the following issues using a nationwide survey in Japan. (1) When obtaining information, to what extent do individuals apply criteria for evaluating information to confirm its reliability; when making decisions, to what extent do people seek out available options and compare pros and cons based on their own values? (2) How strongly are such skills associated with health literacy and demographic characteristics? (3) What opportunities are available to acquire these skills?