...but it never gets better.
PICO was a good first step in trying to describe the process of turning a clinical question into a search strategy. However, it is fundamentally flawed. The problem with PICO cannot be solved by adding more letters onto the end. The problem can only be addressed by understanding what is wrong with PICO, and why so many clinicians find it confusing.
The fundamental problem with PICO is that it de-emphasises the most important question that a person can ask when starting work on their search strategy. That question, as explained to me on the first day of my practicum by my mentor, is: what is the disease or disorder in question?
Medline and other biomedical databases are set up so that the best search results are gained by searching first for the disease or disorder in question. Searching first for the disease or disorder was unquestionably the best advice I ever received for framing a search strategy.
However, every question that I've received from a clinician who had used PICO was missing that fundamentally important piece of information. These omissions resulted in hours of wasted time. In each case, once I finally realised what information I was missing, or queried the clinician and received a clarification, I had to completely revise my search strategy, and immediately began receiving much more relevant results.
A second problem with PICO, or perhaps an extension of the first problem, is that although it is intended as a tool for use by healthcare professionals, it is not written in their language. The very fact that we have to define the word "population" as something other than what a healthcare professional usually means by this term means that PICO fails to communicate with the target audience.
Another problem with PICO is that it assumes that most questions are about interventions, when many are about risk factors, statistics, cost-effectiveness, and other non-intervention topics. Many others do not have a specific intervention in mind, such as the perennial "best practices" request.
The fourth problem with PICO is that the organisation of the components does not correspond well to the order in which the search should be entered into a database. For instance, some of the information falling under population, such as age, species, and setting, are listed first in PICO, but entered last in most search strategies.
On several occasions, when I have mentioned the flaws of PICO to my colleagues who work in various health libraries, many immediately spoke up with great relief, agreeing that it causes more problems than it fixes. Yet it seems that no one wants to be the first to say that the Emperor has no clothes.
The Emperor has no clothes.
But it's not enough to say that there's a problem - that is futile unless it comes with a proposed solution. Let's develop a search frame that emphasises the disease or disorder, uses the target audience's language, and recognises that many questions are not about interventions. Even better, let's develop a search frame that is based on the structure of health databases, so that the clinician using the frame fits their keywords into a structure that readily translates into a database search. Clinicians know what they want to know - what they struggle with is how to tell a database what they want to find. We, as health librarians, are the people with the expertise to develop that translation.
I myself am not yet experienced enough to develop such a frame on my own. However, by pointing out the need for it, and giving a suggestion of what it might look like, I hope to spark the idea for the next tool in the minds of more experienced librarians. Here are some of the elements I think would be worth considering:
- The first element could be the letter D standing for disease or disorder.
- An I for specific interventions could be included although optional
- The next element, also optional, could bring in the idea of risk factors, statistics, etc... unfortunately, the only words I can think of to describe this idea are Information and Demographics, both of which start with letters already taken
- At this point there could be a P for population, including such concepts as age, gender, species, setting, type of patient (inpatient, outpatient, postop, etc...), chronic vs acute, etc..
- An L for limits could be next - this would refer to publication limits (year, type, and language of publication, methodology, peer reviewed, etc...)
If the healthcare professional is going to submit that information to a librarian to do the search, then they can use that framework to create a sentence or paragraph explaining what they want.
However, if they're going to do their own search, the search frame has to indicate what to do with all this data.
- Separate the search terms and search each one individually
- Modify search terms with subheadings
- combine synonyms with OR
- combine concepts with AND
- Refine with limits
- Evaluate current search results
- Look for new search strategies
- Iterate
Unfortunately that spells SMOARELI which is not exactly memorable!
I looked through my literature search requests from the past 6 months, and couldn't find much to add there, but I'm sure there are other and better suggestions out there in the minds of my fellow librarians!
My purpose in creating this post is not to downplay the value of PICO as a starting point. Like the Lamarck's theory or the Bohr atom, it was the first step in describing something very complex. What I'm saying is that PICO is not the end point. Let us not, by adhering too closely to the offering of our Lamarck, fail to inspire our Darwin.
