This video will show you how to do evidence-based research in the MEDLINE database. MEDLINE is an authoritative research database on all topics in the medical field. It is created by the National Library of Medicine and is also freely available on their website as the PubMed database. To get to the database, start at the library homepage and click on resources. There should be a dropdown tab where you will select databases. From the alphabetical list, find MEDLINE or click on all subjects and select health professions. MEDLINE should be listed under the letter M. Go ahead and click on MEDLINE to visit the database. If you're off-campus, you may be prompted to log in.
Now that you have reached MEDLINE, you will want to click on advanced search. Here's an example of a research question. In patients with Crohn's disease, does taking probiotics help with remission or lessening of symptoms? In MEDLINE, we can use the same keyword, Crohn* disease or inflammatory bowel disease and probiotics. We should remember however that terminology can vary between databases. So keep looking out for other terms while we are searching.
Now scroll down to the limiters. We can set the date limiters in MEDLINE just as we can in the database CINAHL. However, MEDLINE does not have checkboxes for peer reviewed or research articles. The best way to limit your search to research articles in MEDLINE is to use the publication type box. If you hold down the control key, you can select more than one publication type. The most important one to choose is clinical trial, since these studies will be considered a high level of evidence. The meta-analysis limiter will retrieve a publications that review the data from multiple research studies. Depending on your topic, you may also want to choose other types of studies, such as comparative study or evaluation study. Let's choose clinical trial and meta-analysis for now. MEDLINE allows you to choose many other limiters, such as English only, human or animal, male or female, or specific age ranges. You can choose EBM, evidence-based medicine reviews, but that will limit your search to that publication type rather than primary research articles.
Now click on search to see the results. Our search retrieved about 50 results. Now let's see what happens when we do a subject search in MEDLINE. MEDLINE calls it's subject heading list MeSH, short for medical subject headings. Like CINAHL headings, MeSH is a very organized and complex system of terms arranged in hierarchies. MeSH headings are not the same as CINAHL headings. So in many cases, you will find that one term might be used in MEDLINE while another might be preferred in CINAHL. So it never hurts to check the list when you switch databases.
The process of browsing for subjects is the same as it is in CINAHL. Click on MeSH 2020 and browse for Crohn's disease. We can see that this database also tells us not to use the apostrophe as in Crohn. If we click on the subject, we get the expanded view of the subject list. As mentioned in our CINAHL tutorial, inflammatory bowel disease is the broader term, and we can check the explode box to search inflammatory bowel disease along with its subheadings and narrower terms.
We can go back and browse the subject list for probiotics as well. Click back to term list. And then at the bottom of the page, click browse additional terms. Once you've typed in and searched probiotics, notice that at the bottom, we have the option to choose probiotics as a keyword rather than a subject. Sometimes a combination of subject headings and keywords can be an effective strategy when you want to be precise on one term but not on the other. Let's do that for probiotics. Don't forget to change your connecting word to and. Click on search. We get over a thousand results. Using these subject headings gave us significantly more articles than keyword searching did this time. Now you should go to the box marked refine your results and click on more to choose your limiters.