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Comprehensive Searching for Health Sciences: Clinical Questions - The Specifics

Transforming an Idea into a Clinical Question

Starting with a general question or idea, you can easily develop a working clinical question in no time! The strategies on this page will help you to make your question targeted and specific, by breaking down your question into meaningful and digestible elements.





PICO Examples

1) Consider the following question: In pregnant women with gestational diabetes, does metformin therapy help regulate blood glucose levels? The PICO might look something like this:


 Pregnant women with gestational   diabetes

I /E

 Metformin drug therapy


 No metformin drug therapy


 Regulated blood glucose levels


2) Imagine that you are studying hand-washing education for nurses and how this affects the spread of hospital-acquired infections. Your PICO might look something like this:


 Hospital acquired infections

I /E

 Nurse hand washing training program


 Absence of hand washing training   program


 Reduced spread of infections


PICO Alternatives

PICO is not the only useful model out there. This link from the City University of London shows some additional ways you could break down your research topic.

For a qualitative question, sometime PS is the most effective way to break down your topic:


 Patient or population



Is "Time" an Important Factor?

The factor of time may also be an important part of your question. For example, you may wonder how effective a drug is over the course of a 6-month long treatment. You could also be wondering how much a disease progresses over a two year period.

If time is an important element of your question, you have the option of adding in the letter T for "time" to your PICO model. You can also add "over ____T___" into your written clinical question.

Inclusion and Exclusion Criteria

Who and what exactly are you studying? As you develop your clinical question, make sure to consider the scope of your question - what is covered by your question and what is not. If the population you are studying is "older adults", what age group specifically do you mean? If you are studying addiction to pain medication, are you referring to narcotics specifically, or any type of analgesic medication?

It is important to have a good understanding of your inclusion and exclusion criteria, so that you can form a specific and targeted clinical question. A vague topic will be confusing for you and anyone trying to understand your research. Keep in mind that these criteria may change as you progress through your search, and this is ok.

What is PICO?

PICO is an acronym used in health sciences searching to break down a clinical question into its meaningful elements. PICO stands for:


 Patient, population or problem you are studying

I /E

 Intervention, indicator or exposure


 Comparison or control that you are measuring against


 Outcome or effect of the intervention, indicator, or exposure


Most clinical questions can be broken down into at least some of these elements, and often all of these elements. Try breaking down your research question into PICO elements, using this printable form.

PICO by Question Type

Here is a table from McMaster University, breaking down the PICO model for different types of questions.

Many question were created by and adapted from McMaster University Health Sciences Library, and are used under a CC-BY-NC-SA 4.0 International license.


McMaster University Health Sciences Library. (2020, February 3). Nursing: Forming questions.

Writing "The Question"

Once you have broken down your question into its PICO elements, you are ready to write a targeted and specific clinical question. The way that you write your question will depend on the type of question that you are asking (see the Clinical Questions - The Basics tab in the subject guide to help you do this).

This handout can help you write your clinical question, according to the type of question you are asking. These guidelines are not prescriptive, and the actual wording of your question will depend on many factors - it will likely be unique to your particular situation.

In general, effective clinical questions will look go something like this:

     For ____P____, does ____I____ compared to ____C____ affect ____O____?

Types of Studies

Different types of questions will require different study types to help answer them. However, whenever possible, it is ideal to select sources that are evidence-based and of high quality. On occasion, the study design is actually a critical part of your research, and it becomes incorporated into your PICO model and clinical question (by adding in the letter S for "study type").

The following pyramid, from Dahlgren University at Georgetown Memorial Library, ranks different types of research articles by how rigorous their research methodology is. Article types that are higher up the pyramid are often the most reliable and evidence-based.


To learn more about Meta-Analyses, Systematic Reviews, Randomized Controlled Trials, Cohort Studies, Case Control Studies, and Case Series, look up these terms in the BMJ Glossary of EBM Terms (alongside many other EBM-related terms).

Animal studies and laboratory (in vitro) studies do not use human subjects, and are therefore not the strongest form of evidence available. Furthermore, case reports only examine one individual patient, and are also not the strongest form of evidence. However, sometimes these types of articles may be the only ones available.

Georgetown University Dahlgren Memorial Library. (n.d.). EBM levels of evidence pyramid [Digital image].