Searching for health information is one of the most common reasons consumers use the Internet. There are a wide range of sources of medical information on the Internet, which can help in finding information on subjects such as medical conditions or disorders, research, drugs and other therapies. These sources include health agencies and institutes, universities, hospitals, laboratories, pharmaceutical industry sites, private companies, publishers, medical libraries, medical networks, support groups and individuals.
High quality, reliable health information abounds on the web. Many people are not aware of these resources and most rely on search engines or directories to find medical information. We have reviewed how search engines and directories work and provided some basic tips to help you improve the effectiveness of your search.
Search engines work by sending computer programs known as "spiders", "crawlers" or "robots" out to search the web. The spider follows the links from page to page, collects the "full text" information, and stores it in the database of the search engine. Google’s database - used by more than 60% of people searching the web - contains more than 8 billion pages.
The problem is that search engines, as they index most of the web, often return a long list of documents that you need to evaluate before deciding what information is useful for you. The Advanced search screen makes your search easier; you can narrow the search to an exact phrase, and select only documents which contain the search terms in their title, using the drop-down menu.
Search engines are effective when using precise terms and specific medical language.
Directories are databases of hand-selected and human-reviewed websites that have been classified by topic into categories, with a description written by the editor reviewing the site.
The logical way to use a directory is to browse it. Browsing a directory refers to reading through category names and clicking your way through the hierarchy of listings until you find the most appropriate category. For example, in the Google directory: Fragile X syndrome (Conditions/Genetic disorders/Fragile X syndrome).
However different directories contain different information and if a website has not been submitted to a directory, you will not find it in that directory’s database. Even maximizing the effectiveness of your search, there are many reasons for disatisfaction with the results provided by search engines and directories:
Non-relevant pages: many pages are unrelated to the information you want. Only 10% of the information available on the web concerns health pages.
Paid placements listings: these pages can be featured prominently on search engine results without regard to quality. Whether or not these listings are labelled as sponsored links, many studies have suggested that most consumers do not see the difference between search results and paid links.
Quality of information: information may be dubious and you must always be discerning about the quality of medical information that you find there.
That’s why, when you use the Internet to look for health care information, specialized tools may be more relevant to help you find accurate and reliable information: specialized search engines (Scirus), gateways (Medline Plus) and databases (Orphanet, PubMed).
Science-specific search engines
Scirus searches about 200 million web pages which have been identified for their scientific content.
It focuses only on these pages and filters out non-scientific sites. It also covers 18 million other documents from medical databases: Medline (14 million bibliographic citations), eMedicine (full-text articles on 7,000 diseases and disorders), BioMedCentral (independent publishing house providing free access to full-text articles on biomedical search), Science Direct (subscription-based information source from hundreds of scientific journals of Elsevier Science), and others.
The advanced search allows users to build a query specifying which data collection (web sources or journal sources) should be searched. Subject areas can also be selected (medicine, life science, etc.). It includes access-controlled sites that other search engines do not index. The results can be ranked according to relevance or by date. With the results displayed, Scirus suggests a list of focus options to further refine the search, which retrieves more specific pages.
Powered by Elsevier Science, the leading international publisher of scientific information, based in the Netherlands, the Scirus search engine is free of charge.
Gateways are search tools displaying information which has been collected, evaluated, then selected and organized to be easy to use, and adapted to the audience level. These gateways are most often produced by medical librarians from public organizations like universities or hospitals.
MedlinePlus is a medical website specially dedicated to consumers. It is maintained by the National Library of Medicine, a part of the National Institutes of Health, both for health professionals and for the general public. MedlinePlus has information from the National Institutes of Health and other trusted sources on over 650 diseases and conditions; information on drugs, clinical trials, health information from the media, and links to many websites, evaluated, reviewed and quality-filtered, including support groups websites. There are also lists of hospitals and physicians, a medical encyclopaedia (adam.com medical encyclopaedia), and a medical dictionary (Merriam-Webster Medical Dictionary).
You can look for information by browsing through the different topics as you do with a directory. MedlinePlus displays the list of all the pages selected for this topic. Links to pre-formulated searches of the top medical database, Medline, allow you to find references to the latest medical articles on your topic.
Or you can use keywords, as you could do with a search engine. The results of your search are displayed in categories, including health topics, medical encyclopaedia, drug information and news. For the category “Health topics”, MedlinePlus displays the specific results for your search, and in addition, other information on specific topics related to your search.
Orphanet is a database of rare diseases and orphan drugs for the general public and for professionals.
Orphanet contains an on-line encyclopaedia, written by European experts, and a list of services for patients and professionals, including information about specialized outpatient clinics, diagnostic laboratories, current research projects, clinical trials and support groups. Searching the database can be done by browsing an alphabetical list of diseases or by typing the name of a disease (the exact name or just the first few characters).
Orphanet is funded by the French Ministry of Health, the French Muscular Dystrophy Association AFM, and the European Commission. It is available in 6 languages (French, English, Spanish, German, Italian, Portuguese). The information is currently collected in 10 European countries, with an extension to 20 shortly. All the information on the website is evaluated by scientific committees in each country, and regularly updated, with a yearly review.
PubMed is a database for professionals. It is a service of the National Library of Medicine which provides access to over 15 million bibliographic citations and author abstracts from more than 4,800 biomedical journals published in the United States and 70 other countries.
You can search by entering one or more terms: the name of an author or the name of a disease for example. The Tab "Limits" allows you to narrow your search: you can limit your search to the title of the documents, to the language, or to the Publication date. The Tab "Details" shows you the search query which was performed on the database. Only professionals can directly use the query syntax. You can just use drop-down menus.
Another way to search PubMed is to use its thesaurus, called MeSH, for Medical Subject Headings. (A thesaurus is a list of terms which is organized, like a directory, from general terms to specific terms). Using MeSH optimizes a PubMed search; if you use synonyms or even alternative terms for the name of a disease, PubMed retrieves the relevant articles.
If you need to keep up with the latest research medical information about a disease and be alerted by e-mail, you can subscribe to a free service of PubMed database, named My NCBI (National Center for Biotechnology Information).
You can save and edit your searches on a specific diseases in My NCBI. The name of the saved search will be included in the Subject of the automatic e-mail update messages.
Another way to receive recent information about rare diseases is to subscribe to a newsletter. For example, Eurordis’ monthly newsletter, or Orphanet’s newsletter, or MedlinePlus newsletters, and many others.
Databases, gateways and specialized search engines are reliable tools to find valuable health information on the Internet. Many other sites have unreliable or misleading information.
1. Specificity of health websites
Health information quality on the Internet needs specific criteria for many reasons:
The internet is unregulated: anyone can publish on the Internet so users should be aware of quality of information;
Different levels of information: from advertising to expert opinions;
Possibility of direct contact with a physician or a researcher;
Protection of personal data;
Possible conflicts of interest;
Variability of opinion among medical experts.
2. Initiatives for better quality for health websites
During recent years, a wide range of initiatives have been taken to improve the quality of the medical Internet:
Listings of evaluated sites: from medical libraries, medical schools, gateways like Medline Plus, support groups, etc;
Guidelines for health information quality: from governments, from many public and private websites, from the European Community via its eHealth initiative. The eEurope 2005 Action Plan, adopted in Sevilla by the Commission on June 2002, affirms that "it is critical that e-health content and services are developed efficiently, are available for all and that health related websites comply with established quality criteria";
Quality seals: from many organisations. If a site has "quality-control" approval from these organisations, a logo is displayed on the site. About 50 quality seals are currently available; but fraudulent logos are also displayed on many websites. Here are some of the main logos you can find on Health websites: Health On The Net, a Swiss Foundation, has elaborated a Code of Conduct to help standardise the reliability of medical and health information available on the web. This Code is now adopted by more than 3000 health sites in the world. URAC (Utilization Review Accreditation Commission) and IHC (Internet Healthcare Coalition) are two other non-profit organizations which provide accreditations to health websites. In France, NetScoring is a set of 97 criteria that can be used to assess the quality of health information on the Internet.
3. Some guidelines for Internet quality of health
All the guidelines and criteria of quality of health websites agree on the following major principles:
Who runs the website? The source of medical information is the first criteria for its credibility and quality and must be displayed. Who is responsible for the content? A University, a hospital, government health agencies, health professionals, support groups, individuals?
Who pays for the website? It costs money to run a website. The source of a website’s funding should be clearly stated. The source of funding can affect what content is presented, how the content is presented, and can allow some assessment of potential conflicts of interest.
How is the information on the website documented? If the person or organisation in charge of the site did not write the material, the original source should be clearly identified. For an original source, evidence on which the material is based should be clearly stated, such as citations of articles in medical journals. The information should have a research basis. Be aware of testimonials or personal stories.
How is information reviewed? Is there an editorial board? What are the procedures for editing the information? Are they clearly stated on the website? Even when these are properly disclosed, it may be difficult to evaluate the credentials of a source. On many websites, healthcare professionals may extend their consultation beyond their areas of training and expertise.
How is information updated? Many resources do not provide a date or details of updating. Websites should be updated on a regular basis. It is particularly important that medical information be current, and that the most recent update or review date be clearly posted. Even if the information has not changed, it is helpful to know that the site owners have reviewed it recently to ensure that the information is still valid.
4. What should you look for when evaluating the quality of health information on websites?
Follow any links to find out as much as you can about the resource:
Search for a section named About us For example on the Orphanet site, the link “About Orphanet” (by country) gives information about the members of the editorial committee. The link to the scientific advisory board (by country) displays the names and qualifications of its members who are in charge of evaluating the information collected by Orphanet. On the eMedicine website, the names of editors for each specialty are listed on specific pages. eMedicine is a private database which contains articles on 7,000 diseases and disorders to which nearly 10,000 physician authors and editors contribute.
Analyse the URL The URL of a web page often provides useful information when evaluating resources, for example .gov in a URL is a good reference because it identifies a government organization, and .edu or .ac identifies educational establishments.
Examine the information contained within the resource. Look for: Dates for the production and updating of materials, as well as details about the frequency and regularity of updating. Indications that the information has a research-basis. Medical facts and figures have references, such as citations of articles in medical journals. For example, Gene Clinics, a NIH database, identifies the evidence on which the material is based. Details of the expertise of the authors online within the text. You can also check the information by searching PubMed.
Be cautious with hyperlinks One characteristic of the Net is the ability to hyperlink. Information on the net is continuous and endless. This means one could be taken away from an apparently rated source of information to an apparently unreliable source without perhaps being aware of it.
Apply critical judgment Even if the information is provided by a trustworthy source, in full compliance with labels of quality and citing the original source, be critical. The last update may be several years ago.
5. Quality seals or self-regulated Internet?
It would be wrong to assume that quality seals are a miracle solution to improve e-health information quality. There are three main reasons for this:
There can not be a single guideline for rating health information on the Net.
Even were all the evaluators to work together using a common tool of evaluation, there would not be enough of them to cover all the medical websites. Many of them are covering the same sites anyway, as naturally they want to propose the quality sites.
It is impossible to guarantee permanent quality for the whole body of information of a medical website due to the ever-changing nature of the content of electronic documents.
A few years ago, the World Health Organization launched a Dot Health initiative to "brand" sites on a global basis with the ".health" URL suffix if they draw information from sources that are determined to be "trustworthy" i.e. complying with certain standards. The experience shows that people’s judgement might be as effective in quality screening as any seal or accreditation. A self-regulated Internet with educated consumers, professionals and media may be the best option.
Genetests (English) Supported by the National Library of Medicine of the National Institutes of Health in the United States. GeneReviews, an encyclopaedia of about 250 diseases, is written and reviewed by experts.
eMedicine (English) A privately-held company, based in the United States, hosts a virtual medical library, which contains detailed, peer-reviewed, and up-to-date information about all medical specialties for 7,000 diseases and disorders. In May 2003, eMedicine launched a new consumer health site, eMedicineHealth, containing articles written by physicians for patients and the general public.
NORD (English) NORD (National Organization for Rare Disorders), a private charity, is a federation of voluntary health organizations, established in 1983 in the United States. Its Rare Disease Database reports are written by medical writers and physicians. Abstracts of disease reports and information about patient organizations are available free of charge. Full-text versions of NORD reports are available for a $7.50 processing fee.
Genetests A directory of genetic testing laboratories and a directory of genetic and prenatal diagnosis clinics.
Information on a clinical trial
ClinicalTrials.gov (English) Developed by the U.S. National Institutes of Health (NIH) in collaboration with the U.S. Food and Drug Administration (FDA), this site provides regularly updated information about federally and privately supported clinical trials. Information on 12,400 clinical studies conducted in the United States and in over 100 countries and sponsored by public agencies or private industry.
NIH: National Institute of Health (USA) A gateway to the 27 Institutes and centers of the NIH: NINDS (Neurology), NCI (Cancer), NEI (Eye) etc. Each of these websites contains a lot of information about hundreds of diseases. For professionals and general public. English and Spanish.