Hello. In this video, you will learn how to use your PICO to build a search strategy that will be used to find resources in the databases.
So what is a search strategy? It is an organized structure of keywords and subject headings used to search a database. Let's take a look at a completed example. It includes words found in the titles, abstracts, and subject headings of results found in the databases. By the end of this video, you will understand what all the different parts are doing.
Let us begin with the three words in all caps. They are called Boolean terms, which you do not need to remember their name, just what they do. AND combines words and therefore narrows the search because all the terms are required to be found. In our example, each result must have at least one of the terms from each parentheses.
Secondly, OR must either have one or the other and therefore expands the search results. In our example, results can have either the phrase "adverse events" or "patient safety" but not necessarily both.
Lastly, NOT eliminates any result with that word and therefore reduces the number of hits. In our example, all hits with a word review have been removed. This will take out most of the review articles in the search. You will begin with your PICO or PICOT, which is population, intervention, comparison, outcome and there may or may not be a timeframe.
We will now work on this example. Do AEDs in the community used by non-professionals increase survival rates in heart attack patients? So my population is heart attack victims. My intervention is AED. My comparison is no AED or you can think of it as a control. The outcome is survival rates increase.
When you begin your initial search, you will want to work with only a couple of the concepts at a time. Also, you want to select the most important words from PICO to be part of your search. We will begin with part of the intervention, AED, and part of the population description, heart attack. If you have an acronym like this one, you will want to find out what it stands for before doing any searches.
You will want to perform your initial search in at least two databases. I have chosen to use PubMed and CINAHL. In PubMed, this search resulted in 205 hits. None of the first 20 or so were on my PICO. In CINAHL there were 686 hits and several of the first hits were close to my topic. Therefore, before adding anything more to the search, we will check these to see if they can help fine-tune the search. They contain the word layperson, which I can use as a keyword for my concept in my PICO non-professionals. When you look at the detailed record, you should look at the title, the major subject headings. In this example, there are subject headings for two of my concepts. Heart attack subject heading is heart arrest, and there is a subject heading for AEDs.
And lastly, you'd want to look at the abstract. Now I will add in the new concept of layperson to my search and try again in CINAHL. EBSCOhost databases remember common searches and can help you find more keywords. Just remember that in all other databases, the OR needs to be in all caps. I will now try this new search in PubMed. It results in only 17. One of the reasons why the drop in results could be that the subject headings do not match between the two databases. PubMed uses MeSH while CINAHL has its own subject headings. It appears that defibrillators automatic external is not a MeSH term.
Also in the subject heading there is a new term, cardiopulmonary resuscitation. This along with the subject headings from MeSH have now been added to my search strategy. From the results in CINAHL, more search terms were discovered. Firstly, in the title of this one, we have a new word to add to our layperson or public search terms, which is community. Secondly, in the abstract, the phrase public access defibrillation was found.
Lastly, another key word for the concept of non-professional was found, which was bystander. So we add those into our search terms. And also now we are ready to add the search terms about the outcomes. Remember to use broad terms and do not include words like reduced or increased. You can also use terms that are opposite of your original concept. The goal of this example PICO is to increase survival rates, but that also means it will reduce mortality.
This is the search strategy at this point. The defibrillators part has been simplified. Also, phrases have been put in quotations, which searches for the phrase instead of each individual keyword, which should eliminate some of the hits that are not about the topic. After a few tries in PubMed and CINAHL, just putting public access in quotations worked best. The number of results in both PubMed and CINAHL were a little high. There are three possible adjustments that can be tried. Firstly, if you only want articles in this country, use the search U.S. or United States in quotations. This will remove most studies done outside the United States.
Secondly, you can use the NOT to remove studies that are not about your topic. For this example, a good one would be first responders.
Lastly, you can limit the search of the terms to just the subject headings. Databases handle subject headings differently. In CINAHL and other EBSCOhost databases, it's best to use the dropdown choices. On the other hand in PubMed and Cochrane, you need to use the code for the MeSH heading.
Things to remember when you are building a search strategy: This is a process and it will change over time as you find more articles about your PICO. If you find what you think of as the perfect article, use the words found in it to rework your search strategy. And remember, you can always contact the health sciences librarian for assistance in developing your search strategy.