Weighing the Evidence: PICO Questions: What Are They, and Why Bother?

Virginia Moyer

doi:10.1542/gr.19-1-2

In this month’s issue of AAP Grand Rounds, we introduce a new feature: the PICO question. PICO is an acronym that describes the elements of a well-formed clinical question. The structure includes:

“P” for the patient or problem “I” for the intervention of interest “C” for comparison, and “O” for outcome.

For example, a parent might ask whether a single shot of a steroid would work as well as five days of oral steroids for a young child sent home from the ER after an asthma exacerbation.

The clinical question in “PICO format” would be: “Among young children with acute asthma exacerbation, is a single dose of IM dexamethasone comparable to five days of oral prednisolone for resolution of asthma symptoms?”

PICO questions can help clinicians find relevant and useful information, not only from searching databases but also from their consultants.¹ Having carefully structured the question, a MEDLINE search using the key words in the PICO question above would be highly likely to yield the study by Gordon. Just as a good PICO question can help a clinician find useful information, a good PICO question can guide clinical research. Many clinical research studies are designed to answer just this sort of well-structured clinical question.

Starting this month, each study that addresses a clinical question will be accompanied by the PICO question – readers will be able to judge how well the investigators do at answering these questions!

The PICO format works best for questions about therapies or other interventions (things we do to patients) but can be modified slightly to describe studies of diagnostic tests, prognosis, or studies about the possible causes of a problem.

For example, for an article about a diagnostic test, the “outcome” will be the accuracy of the test: “Among children with suspected hypercalcuria, does Ca/Cr ratio accurately reflect 24-hour urinary calcium?” and for a question about harm, the “intervention” will be an exposure: “Among children with acute otitis media due to Streptococcus pneumoniae, does exposure to PCV7 vaccine result in a greater likelihood of antimicrobial-resistant organisms?” Of course, some studies abstracted in AAP Grand Rounds do not attempt to answer a specific clinical question, but instead describe a population or discuss an important general issue (the latter is particularly likely among bioethics articles). The PICO question will not be appropriate for these sorts of abstracts.

We believe the addition of PICO questions will add value for AAP Grand Rounds readers by clarifying the study question. We welcome your comments by using the “e-letters” feature at www.aapgrandrounds.org.