May 2021 Volume LVI Number 3


Evidence-Based Dentistry (EBD) PICO

November 2013 Volume XLIX Number 6

 "A great deal of influence rests in the hands of parties who control the framing of a health issue" K.D. Brownell and K.E. Wagner 1

This article is the second in a series explaining evidence-based dentistry and how it is used in the practice of pediatric dentistry.In the September PDT, we provided an overview of what EBD is and introduced you to our EBD Committee. As this article goes to press, Academy staff members, your peers and outside experts steeped in evidence-based practice, have had their inaugural guideline meeting.

At the meeting, the formulation of the PICO question was begun. PICO questions are required to form evidence-based answers because, unlike general questions, such as classification of caries, that are often answered using textbooks, complex clinical questions require unpronounceable acronyms.
You may be asking, what's a PICO question? You say pie ko, I say pee ko -- however it's pronounced, PICO stands for the essential parts of an evidence-based question, they are:

P = Patient, Population, Problem


I = Intervention, Prognostic Factor, Exposure (What main intervention are you considering? What is the main alternative being considered?)


C = Comparison (also None or placebo) (What are the alternatives to the intervention?)


O = Outcome (What are you trying to achieve, measure, improve or affect? Outcomes may be disease-oriented or patient-oriented.)2

The first step of any evidence-based process is dissecting one's question into parts. These parts define what evidence is important to answering your clinical question.


Researchers use PICO for complex questions that affect clinical decisions. Complex or novel clinical queries require a search of the primary medical literature using the PICO format.


For example, here's how to break down this clinical question: In children with dental caries will xylitol gum chewing, as compared to no xylitol gum, result in a decreased incidence of caries?:

Patient/population/problem        children w/ dental caries
Intervention                                        xylitol gum 
Comparison                                       no xylitol
Outcome                                           decrease in incidence of caries 

Once you have your question in PICO format, you can use the terms that you have identified in your literature search. PubMed, the most widely-used database for evidence-based research, indexes health sciences literature using MeSH (medical subject headings). By breaking down your question, you prepare it to be parsed by databases. A well-formulated question will facilitate the search for evidence and will assist you in determining whether the evidence is relevant to your question.


Next issue, a step-by-step guide to search for the evidence using PubMed!


1Brownell KD, Warner KE. The perils of ignoring history. Milbank Q. 2009 Mar;87(1):259-94.


2 Evidence Analysis Manual: Research and Strategic Business Development Academy of Nutrition and Dietetics January 2012