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Planning a structured search in health (Open Learning)

What is PICO, PIO and PEO?

For Evidence Based Practice (EBP) searches, you will often be expected to break down your question into its key concepts using an EBP formula such as PICO, PIO or PEO.

  • PICO: Population/Problem/Patient; Intervention/Issue; Comparison; Outcome
  • PIO: Population/Problem/Patient; Intervention/Issue; Outcome
  • PEO: Population/Problem/Patient, Exposure, Outcome

Using a framework like PICO can be useful as it prompts you to make a clear, structured and focussed question. It ensures that you include the important elements of a clinical research area: Patient, Intervention/Issue/Exposure, Comparison (if appropriate) and Outcome, which then creates a structure for your search strategy. 

PICO questions and PIO questions may focus on quantitative or qualitative research. When there is no comparison element, as with many qualitative research questions, the search strategy can be defined as following a PIO model. The I part of the framework may focus on a specific intervention that a patient/population group has received or it could be a particular issue that a patient/population group faces.

PEO questions are generally used for qualitative research where the population has been exposed to a condition or illness (e.g. dementia), to a risk factor (e.g. smoking), to screening, to rehabilitation or to a service.

PICO/PIO

P - Population, Problem, Person of Interest

Who is the question about?

I - Intervention/Issue

What is happening or being done to P? 

C - Comparison (not always used)

What could be done instead of I?

O - Outcome

What has happened to P as a as result of I?

 

Example PICO Questions:

In patients at high risk for gallbladder dysfunction (P) is a HIDA scan (I) compared with an ultrasound (C) more accurate in diagnosis (O)?

Patient Patients with gallbladder dysfunction
Intervention HIDA scan
Comparison  Ultrasound
Outcome Diagnosis

In obese females (P), how does weight loss (I) compared to daily administration of ACE inhibitors (C) affect blood pressure (O)? 

Patient Obese females
Intervention Weight loss
Comparison  ACE inhibitors
Outcome Blood pressure

 

Example PIO Questions:

How do elderly patients in orthopaedic rehabilitation (P) who have been separated from significant pets (I) perceive their motivation to progress (O)? 

Patient Elderly patients in orthopaedic rehabilitation
Issue Separated from significant pets
Outcome Motivation to progress

Are children (P) who have parents with high BMI (I) at increased risk of obesity (O)?

Patient Children
Issue Parents with high BMI
Outcome Obesity

(Adapted from Melnyk and Fineout-Overholt, 2019) 

PEO

P - Population, Problem, Person of Interest

Who are the affected population?

E- Exposure

Is the population exposed to a condition or illness or to a risk factor?

O - Outcome

What are the outcomes or themes?

 

Example PEO Question:

What are the attitudes (O) of health professionals (P) towards caring for older patients with dementia (E) in an acute setting (P)?

Population Health professionals in an acute setting
Exposure Older patients with dementia
Outcome  Attitudes

Does bullying (E) increase the chances of teenagers (P) developing an anxiety related disorder (O)? 

Population Teenagers
Exposure Bullying
Outcome  Anxiety related disorder

(Adapted from Colorado State University, no date; University of Suffolk, no date)