PEO Framework for Developing Answerable Research Questions | A Guide to Formulating Qualitative and Quantitative Research Questions with PICO and Literature Searching

Understanding the PEO Framework for Developing Research Questions

What is the PEO Framework and How Does it Apply to Research?

• The PEO framework is a structured tool used to develop research questions in both qualitative and quantitative studies, particularly in health sciences.
• PEO stands for Population, Exposure, and Outcome—the three key components that guide the formulation of research questions.
• It is particularly effective in addressing clinical questions, as it enables researchers to clearly define their phenomenon of interest and the population they aim to study.
• The PEO framework helps in creating well-defined research questions, which are essential for conducting systematic reviews or designing a study.
• The framework allows for literature searching to focus on the most relevant studies by identifying the study participants, the type of exposure they are subject to, and the expected outcome.

The Importance of Using a Framework in Research Question Development

• Using the PEO framework enhances the clarity of research and practice by narrowing down the research topic to its most essential components.
• A well-defined research question is crucial for evidence-based practice because it helps in identifying specificity and ensures the question is answerable.
• Frameworks like PEO guide researchers in choosing the correct study design, whether for qualitative or quantitative research, by ensuring the question aligns with the study’s methodology.
• The PEO framework enables translational research, providing actionable insights that contribute to clinical outcomes and better patient care.
• PEO helps in formulating research questions that are aligned with best available evidence, ensuring that the studies contribute meaningfully to the scientific community.

Types of Research Questions in Qualitative and Quantitative Studies Using the PEO Framework

• Quantitative Research Questions: These questions often use the PEO framework to examine relationships between exposure and outcome in a population. They are useful in randomized controlled trials or clinical studies where data can be measured and analysed.
  • Example: “What is the effect of a new medication (exposure) on blood pressure (outcome) in adults with hypertension (population)?”
• Qualitative Research Questions: In qualitative studies, the PEO framework can help researchers focus on exploring experiences, perceptions, or behaviors of the population in response to certain exposures.
  • Example: “How do individuals with chronic pain (population) perceive the impact of physical therapy (exposure) on their daily lives (outcome)?”
• The PEO framework can be applied in a wide range of research methods, from observational studies to clinical questions aimed at improving healthcare practice. By clearly delineating the phenomenon of interest, the framework ensures that researchers do not stray from the focus of the study and can formulate precise research questions.
• In qualitative studies, the PEO framework also aids in the literature review process by guiding researchers towards studies that address the same or similar research questions. This can facilitate a more targeted search strategy, reducing the time spent on irrelevant articles.
• Using the PEO framework allows for a more systematic approach to data collection and data analysis, ensuring that the study remains focused and that findings are more likely to be meaningful and applicable to real-world clinical outcomes.
• In both quantitative and qualitative research, the PEO framework ensures that questions are not just answerable, but also relevant to the research’s goals and feasibility.

By applying the PEO framework during the development of research questions, researchers can ensure that their studies are rooted in existing theories and previous studies, contributing valuable knowledge to the scientific inquiry process. This ensures that questions are scientifically valid, thus improving the overall quality of research studies.

Question Type	Population (P)	Exposure (E)	Outcome (O)
Therapy	Adults with chronic lower back pain	Physical therapy focusing on posture correction exercises	Improvement in mobility and reduction in pain levels
	PEO Question: In adults with chronic lower back pain, does a physical therapy regimen focused on posture correction improve mobility and reduce pain compared to standard pain management treatments?
Diagnosis	Children with recurrent headaches	MRI imaging for brain abnormalities	Accurate diagnosis of potential underlying neurological conditions
	PEO Question: In children with recurrent headaches, does MRI imaging for brain abnormalities provide a more accurate diagnosis compared to routine physical examination and history-taking?
Prognosis	Elderly patients recovering from hip fractures	Rehabilitation program focusing on strength training	Rate of recovery in mobility and independence
	PEO Question: In elderly patients recovering from hip fractures, does a rehabilitation program focusing on strength training improve mobility and independence compared to standard post-operative care?
Etiology or Harm	Teenagers who smoke	Regular vaping	Development of respiratory conditions
	PEO Question: In teenagers who smoke, does regular vaping increase the risk of respiratory conditions compared to those who do not vape?
Prevention	Adults with high cholesterol	A diet low in saturated fats and high in omega-3 fatty acids	Reduction in cholesterol levels and improvement in heart health
	PEO Question: In adults with high cholesterol, does a diet low in saturated fats and high in omega-3 fatty acids help reduce cholesterol levels and improve heart health compared to no dietary changes?

Final Thoughts on Using the PEO Framework for Research

• The PEO framework is a powerful tool for both qualitative and quantitative research as it helps to create well-defined and relevant research questions.
• By clearly identifying the population, exposure, and outcome, researchers can use this framework to guide the methodology, ensuring the study’s design aligns with the overall research objectives.
• It enhances the search strategy and improves the rigor of literature searching, enabling researchers to gather comprehensive literature that directly informs the research.
• Whether your research is focused on improving clinical practice, advancing evidence-based medicine, or contributing to the field through systematic reviews, the PEO framework ensures that your research questions are focused, answerable, and aligned with the best available evidence.

Get Quick Access to Other Key Research Question Frameworks Below

• Learn how to craft effective and achievable goals by reading the article on how to Write SMART Objectives | Best 5 Tips in Writing SMART Goals.
• Explore key tips on how to craft strong and focused research questions for successful outcomes in your studies by reading the article about Sample Research Questions | Tips for Good Research Questions.
• Discover how the PCC framework can help structure clear and effective research questions for your scoping review by reading the article about PCC Framework | Best for Scoping Review Research Questions.
• Learn how the SPIDER framework can guide you in formulating well-defined qualitative research questions by reading the article about SPIDER Framework | Formulate Qualitative Research Question.
• Understand how to use the PIO framework to create focused clinical research questions for your practice by reading the article about PIO Framework for Formulating Clinical Research Questions.
• Find out how the PICO framework can enhance your ability to create evidence-based research questions for clinical research by reading the article about PICO Framework for Evidence-Based Research Question.
• Uncover the power of the SPICE framework in crafting systematic review research questions that yield comprehensive findings by reading the article about SPICE Framework for Systematic Review Research Questions.
• Explore a 5-step guide to formulating PICOT questions for nursing research, optimizing clinical evidence-based practice by reading the article about PICOT Framework | 5 Steps Guide in Nursing PICOT Questions.

Formulating Effective Research Questions with the PEO Framework

Key Elements of a Good Research Question in the PEO Framework

• Clear and Focused: A research question developed using the PEO framework should be specific and focused. It must clearly define the population, exposure, and outcome to ensure the study remains targeted.
• Relevance: The question should align with the phenomenon of interest in the context of the study, whether it is for quantitative or qualitative research. The PEO framework helps ensure that questions are grounded in real-world issues, addressing clinical outcomes or improving practice in evidence-based medicine.
• Answerable: The PEO framework ensures that the research question can be answered within the constraints of the study. This includes defining measurable outcomes, whether in clinical settings or broader populations.
• Ethical Considerations: A good research question adheres to the principles of ethical research, ensuring that the study design considers the safety and well-being of participants, in line with ethical guidelines from organisations like the National Institutes of Health.
• Alignment with Existing Literature: The PEO framework encourages a literature review to ensure the research question is built on previous studies. This helps validate the research question within the context of what has already been explored, ensuring the study is grounded in evidence-based practice.

Step-by-Step Guide to Formulate Research Questions with PEO and PICO

1. Define the Population:
   • The PEO framework starts with clearly identifying the population under study. This could be a specific age group, disease group, or a subset of individuals with a particular characteristic.
   • Example: “Adults over 50 years with Type 2 diabetes.”
2. Specify the Exposure:
   • The next step is to define the exposure or intervention being studied. This could be a medical treatment, lifestyle change, or any other influencing factor.
   • Example: “A 12-week dietary intervention.”
3. Determine the Outcome:
   • Identify the expected outcome or what the study seeks to measure, such as changes in a clinical marker or improvement in health conditions.
   • Example: “Reduction in blood glucose levels.”
4. Refine with PICO (for Quantitative Research):
   • Once the PEO framework is used to define the question in terms of Population, Exposure, and Outcome, the addition of PICO (Patient/Problem, Intervention, Comparison, Outcome) can refine the question for quantitative research.
   • Example: “In adults over 50 with Type 2 diabetes (P), how does a 12-week dietary intervention (I) compared to standard care (C) affect blood glucose levels (O)?”
5. Incorporate Qualitative Elements (for Qualitative Research):
   • For qualitative studies, the PEO framework guides the development of questions aimed at exploring perceptions, experiences, or behaviours. In qualitative research, you might not always have a specific comparison group or control.
   • Example: “How do adults with Type 2 diabetes perceive the impact of a dietary intervention on their daily life?”
6. Validate the Question with Literature:
   • Before finalising the research question, a comprehensive literature search using LibGuides or databases like PMC ensures the question aligns with existing research and fills gaps in knowledge. This process often includes checking for coherence with previous studies.

Common Pitfalls to Avoid When Developing Research Questions Using the PEO Framework

• Overcomplicating the Question:
  • Avoid making the research question too broad or complex. A clear and concise question ensures focus. The PEO framework is designed to break down complex issues into manageable components, so questions must remain specific.
• Neglecting Feasibility:
  • A good research question is not only important but feasible within the study’s scope. It is critical to ensure the design of the study aligns with available resources and time. Questions that require data or populations that are not accessible can be difficult to answer.
• Ignoring Ethical Considerations:
  • Ethical research is paramount. The PEO framework helps to create questions that ensure the safety and well-being of participants are considered. Ignoring these aspects can undermine the integrity of the study and its findings.
• Not Aligning with Study Design:
  • The PEO framework helps to ensure that the research design and methodology match the research question. Ensure that the question is appropriate for the chosen study design, whether observational, experimental, or a systematic review.
• Failure to Use Established Frameworks:
  • Using the PEO framework alongside frameworks like PICO or other common frameworks helps ensure the question is robust and comprehensive. Avoid creating research questions in isolation without referring to well-established methodologies that can improve the question’s precision and scope.
• Lack of Clear Outcome Definition:
  • A major pitfall in formulating research questions is the failure to clearly define the expected outcome. A vague or undefined outcome leads to an unfocused study. The PEO framework ensures outcomes are clearly delineated, making the research easier to conduct and interpret.

By using the PEO framework, researchers can develop well-formulated research questions that are specific, answerable, and aligned with the best available evidence. These questions are instrumental in guiding the study design, the methodology, and the analysis of the research findings.

Aspect	PEO Framework	PICO Framework
Components	Population, Exposure, Outcome	Patient/Problem, Intervention, Comparison, Outcome
Type of Research	Primarily qualitative or observational research	Primarily quantitative research, often clinical trials
Comparison Group	No comparison required; observational or descriptive focus	Comparison group is required (e.g., control group, placebo)
Focus	Focus on understanding the relationship between population and exposure	Focus on comparing the intervention with a comparison group to evaluate its effectiveness
Ideal For	Studies without intervention or treatment (e.g., risk factors, public health studies)	Studies with interventions (e.g., clinical trials, treatments)
Use Case	Useful for observational studies, public health research, epidemiology, and qualitative studies	Ideal for clinical trials, interventional research, or studies evaluating treatment effects
Example Question	In elderly patients with osteoarthritis (Population), does physical activity (Exposure) improve joint mobility (Outcome)?	In elderly patients with osteoarthritis (Patient/Problem), does physical therapy (Intervention) improve pain levels (Outcome) compared to standard pain medication (Comparison)?

Implementing the PEO Framework in Literature Searching and Research Practice

How to Use the PEO Framework for Efficient Literature Searching

• Focus on Key Components:
  • The PEO framework helps streamline the literature search by focusing on three key components: Population, Exposure, and Outcome. Researchers can use these components to filter relevant studies, ensuring that only studies addressing the same or similar research questions are included.
  • Example: Searching for studies on Type 2 diabetes (Population) and the effect of dietary interventions (Exposure) on blood glucose levels (Outcome).
• Guides Database Searches:
  • The PEO framework ensures that the literature search is focused and systematic. Using this framework, researchers can define their search terms based on the three components, increasing the chances of finding highly relevant articles, such as those in Cochrane or Journal of Medicine.
  • For instance, the PEO framework can help refine searches in databases like PMC, filtering by research design and key variables.
• Incorporate PICO:
  • Researchers can extend the PEO framework by incorporating PICO (Population, Intervention, Comparison, Outcome) when searching for quantitative research articles. This further refines the search, providing studies with clearly defined control groups and measurable outcomes.
  • This combination of PEO and PICO ensures that the search results are both relevant and comprehensive.

Feasibility of PEO Framework in Various Research Types and Disciplines

• Wide Applicability:
  • The PEO framework is highly flexible and applicable to both quantitative and qualitative research questions. Whether you’re working on clinical trials, observational studies, or qualitative interviews, the PEO framework can be adapted to fit the research context.
  • Example: A quantitative study might focus on the effectiveness of an intervention, while a qualitative study may explore experiences or perceptions related to the same intervention.
• Enhanced Study Design:
  • The PEO framework is also applicable across different disciplines, including the health sciences, where it helps structure research questions for clinical studies, systematic reviews, and other types of research.
  • By ensuring that each component of the PEO model is addressed, researchers can create questions that are feasible, specific, and relevant to their area of interest.
• Scalable for Large Studies:
  • The PEO framework is particularly beneficial for large-scale studies or systematic reviews, such as those conducted by organizations like Cochrane. It allows researchers to systematically address the problem and refine their questions, ensuring that studies are comprehensive and well-defined.

Bridging the Gap Between Research and Practice with the PEO Framework

• Improves Clinical Relevance:
  • The PEO framework helps bridge the gap between research and practice by ensuring that research questions are directly applicable to real-world clinical scenarios. This is particularly important for evidence-based medicine, where research findings must have practical applications in healthcare.
  • Example: The PEO framework allows researchers to focus on practical issues, such as how an intervention might improve patient outcomes, making it easier to translate findings into everyday practice.
• Translates Research into Action:
  • By using the PEO framework, researchers can ensure that their studies provide actionable results that address real-world issues. The framework helps in formulating research questions that focus on improving clinical outcomes, which are essential for improving patient care and healthcare practices.
• Supports Ethical Research:
  • The PEO framework ensures that ethical research principles are followed by clearly defining the population and exposure to ensure that the research is both feasible and respects participants’ rights. This is key in bridging the gap between research and practice, as findings will be ethically sound and directly useful for improving practices.

PEO framework plays a critical role in literature searching, study design, and bridging the gap between research and practice. By incorporating PEO and PICO in research, researchers can ensure that their questions are answerable, relevant, and aligned with the best available evidence.

Frequently Asked Questions About PEO Framework

What is the PEO framework used for?

The PEO framework is primarily used for developing well-defined research questions, particularly in healthcare and clinical research. It helps researchers clearly identify the population, exposure (or intervention), and outcome in a study. This framework ensures that the research question is focused and answerable, making it easier to design the study, conduct literature searches, and analyze results. It is applicable for both qualitative and quantitative research questions, facilitating evidence-based practice by providing clarity on the critical components of a research question.

What is the PEO format for research questions?

The PEO format for research questions consists of three main components: Population (P), Exposure (E), and Outcome (O). The Population refers to the group of individuals being studied, such as patients with a specific condition or demographic. The Exposure is the factor or intervention being investigated, such as a treatment or lifestyle change. The Outcome is the result or effect that the study aims to measure, such as changes in health status or behavior. This format ensures the question is focused, specific, and relevant to the research context.

What is an example of a PEO research question?

An example of a PEO research question could be: “In adults aged 60 and above (P), how does a 12-week exercise programme (E) affect their cognitive function (O)?” This question is structured using the PEO framework by clearly identifying the population (older adults), the exposure (exercise programme), and the outcome (cognitive function). This format ensures the question is specific and can be effectively researched, providing a focused direction for the study’s design, methodology, and analysis.

What is the framework for formulating research questions?

The framework for formulating research questions is the PEO framework, which stands for Population, Exposure, and Outcome. This framework provides a structured approach to developing clear and answerable research questions. Researchers begin by defining the population of interest, the exposure (such as an intervention or condition), and the outcome (the effect or result they wish to measure). This helps ensure the research question is focused, relevant, and feasible. Additionally, for quantitative studies, the PICO framework can be used in conjunction with PEO to refine the research question further.