Nowadays, anyone who receives a medical diagnosis or is simply curious about some aspect of medicine often turns to the Web. Typically, people will try one of the major search engines such as Google. If you’ve experimented at all with online searching, you have seen the incredible number of “hits” that can be retrieved—often in the hundreds of thousands or even millions. For example, a simple search of Google on lung cancer finds over twenty-seven million pieces of information. If you use Google’s advanced search technique to find that specific phrase (click on Advanced Search or enter the words within quotation marks), this reduces the results to just fewer than ten million pages—hardly a manageable amount.
Selecting the most authoritative articles from this huge mass of information is challenging. While there are general guides for trying to judge the value of web pages, there is a better way. With a little practice, you can access the same detailed medical information that health care practitioners use. In the next paragraphs, I’ll describe some basic ways to fnd information in the major medical databases.
The largest and most respected collections of online information are the U.S. National Library of Medicine (NLM) databases. Before the days of general public access through the Web, the NLM maintained a computer database of medical information called Medline. All of this information and considerably more is now available to anyone with Internet access. General access is through a service called PubMed. You can visit the starting point through this link: U.S. National Library of Medicine
There is a detailed section on how to get the most out of these databases, accessible by following the link on the left of the page to ENTREZ HELP.These databases include more than sixteen million reports and other articles from MEDLINE and other life science journals dating back as far as the 1950s. PubMed includes links to full text articles and other related resources.
The U.S. National Library of Medicine link brings you to a search page. With so many articles and books indexed, just typing in a simple phrase like lung cancer today found 124,849 references. (All uses of retrieved numbers of citations in this article are examples taken from a search at the moment of writing; the results change constantly.) Even using quotation marks to restrict the search to the phrase only reduced the result to 49,882. This is where some more sophisticated searching techniques come into play.
If you can, it will be much easier to understand this process if you open a separate browser window and follow along with the examples described here. To help interpret the directions below, words that will be searched as examples are italicized. Terms that represent clickable buttons on the Web pages are in capital letters.
The phrase lung cancer seems to be the obvious way one might look for information on this disease. However, medical personnel, particularly researchers, do not always use common terms. So you might start by checking what the official term is for a specific condition. On the left of the home page (National Library of Medicine )is a list of links. In the second section on the left, under PubMed Services, you will see the words MeSH Database. MeSh stands for Medical Subject Headings. Clicking on this link takes you to a page to search this database. You also will see some short tutorials, in both audio and visual format, on how to conduct a search. I urge you to take the time to explore these quick tours to improve your skills.