The manual evaluation of Persian language websites showed that the Ebola-related websites were of poor credibility because none of those websites met all the eight HONcode criteria (Table 2). The results of this study were consistent with the research results of Ebola English-language websites . Furthermore, the results of the present study were consistent with the results of similar studies conducted on the evaluation of non-Persian language websites in other health topics. Their findings showed unreliability and poor quality of health websites [34,35,36,37].
None of the Persian language websites evaluated at the present study was officially approved by the HONcode foundation, while the study on English language websites on Ebola showed that seven websites were approved officially . It is not out of the mind that this lack of credibility exists in Ebola-related websites in other languages, and that the websites do not have good credibility, although there is a need for detailed studies in this regard. Therefore, users must act with full awareness when using the Persian-language websites as a source of health information regarding Ebola, and they must use the provided information alongside expert medical advice from relevant experts .
In the current study, overall, the justifiability criterion obtained the highest score (Table 2). These findings show that the majority of the websites related to Ebola diseases try to present the correct information and the actual performance of a particular treatment, drug, or medical device, and their related consequences. However, still, there is lack of honesty in expressing material or commercial use in 11% of websites.
The authority criterion obtained the lowest score (Table 2). Only 16% of the websites had specified the name and expertise of authors. However, the compliance with this criterion reflects the credibility and reliability of the information resource, because this principle proves that health information provided on the intended website that has only been given by qualified professional resources and written by experts is more reliable .
The complementarity criterion has been considered in most of the surveyed websites (79%). The compliance with this criterion shows that the surveyed websites try to guide the people to visit a physician instead of making health decisions just based on online information . Nevertheless, still, 21% of surveyed websites have not paid attention to this criterion that may lead to the misuse of information.
Transparency principle is considered in just 21% of the surveyed websites. This principle indicates that in case of requiring additional information, people must be able to connect with content editors and to communicate with webmasters. Regarding that 79% of the Ebola-related websites have not considered this principle, it is necessary to website owners to modify their websites to help individuals to get additional information.
Attribution policy has been considered in just 48% of the surveyed websites. It is necessary to specify the publication date as well as the latest updating of the content. This principle, in fact, helps to ensure the credibility of the written medical content. Medical content must continually be updated, in the event of non-compliance with this principle, the date is not revealed. Regarding that 52% of the Ebola-related websites had not identified the source of information or the last update date, people should be aware of the unreliable or outdated information. Therefore, it is recommended that the health websites and consequently health information retrieved by general search engines be used with more caution.
The advertising should be clearly distinguished from editorial contents, but advertisement policy was less considered in the surveyed websites (56%) which was mostly retrieved by Google search engine. Failure to comply with this principle indicates that the individuals may not be able to distinguish the advertisement information from the main content. Thus, their trust in marketing information may mislead them to unreliable information which threatens their health.
The health websites including all types of websites (organizational, commercial, governmental, etc.) must include the declaration of the funding resources as well as the declaration of all conflicts of interest. While in the present study, just 35% of the surveyed websites have declared financial disclosure. Failure to comply with this principle indicates that the website may recommend the various medical interventions that have a hidden marketing aspect. Thus, encouraging the individuals to use medication or a therapeutic method, and the individual’s trust in such information, may have irreparable consequences for them.
According to the results obtained from each search engine, Google, Yahoo, and Bing, it was found that none of the evaluated websites had considered all eight criteria. In terms of considering the authority criteria, amongst the three selected search engines, the websites returned by Google were in better condition (Table 2). Regarding the complementarity, attribution, justifiability, and financial disclosure criteria, it seems that the webpages retrieved by Bing are in better condition than Yahoo and Google. Regarding the advertising policy, transparency, and privacy principles, the webpages retrieved by Yahoo are in better condition. Meanwhile, the status of websites retrieved from the Bing search engine was generally better than other search engines and Google was worse than the others, although the difference was negligible (Table 2).
Most of the retrieved websites in this study (Fig. 2) were commercial [62%], similar to the results reported in other studies conducted to evaluate the health websites , though commercial websites have lower quality compared to other websites [22, 40,41,42]. The government and university websites generally are aimed to educate people . In this study, 10% of retrieved websites were of governmental type. Furthermore, just 4% of the retrieved websites were of the university type. The university websites, which a person would tend to trust more, showed no significant advantages in credibility compared with other types of websites. While the university websites are expected to highly consider the HONcode of conduct principles, but the present study findings revealed that they are not so, as the findings of studies on other health topics [34, 44]. Thus, looking for health information on Ebola, the individuals may encounter less credible websites which may include information that is more commercial than educational. Consequently, they may receive information that is harmful to their health. Moreover, in this study, 24% of the retrieved websites were organizational type in which patients can access to some records on health issues such as future appointments, history of past visits, and the patient laboratory results. This type of website also did not show any significant advantages in reliability compared with other types of websites. Thus, individuals searching for Ebola-related information must use all types of health websites with caution.
In the current study, the 62 evaluated Persian websites are samples of the websites that Persian language users will face when searching for information about Ebola. Failure to comply with all HONcode criteria in these websites shows that while searching on the Internet, Persian language users will encounter none credible websites and consequently low-quality information that can affect their decision about the prevention and treatment of Ebola. This highlights the importance of understanding the quality of online health information by physicians and how to guide patients to reliable sources and high-credible websites .
This study was faced with some limitations. The “Ebola” keyword was searched in April 2016. Therefore, this study cannot completely and comprehensively represent other searches at different times. On the other hand, due to the dynamic characteristics of the web, the results of the search will vary at different times and in different places. New websites are constantly created, while some websites are disbanded. On the other hand, the present study was conducted only on Persian-language websites. The results of this study may be different from the results of studies conducted in other languages, although the previous research by the researcher on English-language websites was consistent with the results of this study.