Skip to Main Content
Library Guides

Systematic Reviews

Using a framework to structure your research question

Your systematic review or systematic literature review will be defined by your research question. A well formulated question will help:

  • Frame your entire research process
  • Determine the scope of your review
  • Provide a focus for your searches
  • Help you identify key concepts
  • Guide the selection of your papers

There are different models you can use to structure help structure a question, which will help with searching.

Selecting a framework

A model commonly used for clinical and healthcare related questions, often, although not exclusively, used for searching for quantitively designed studies. 

Example question: Does handwashing reduce hospital acquired infections in elderly people?

P Population Any characteristic that define your patient or population group.  Elderly people
I Intervention What do you want to do with the patient or population? Handwashing
C Comparison (if relevant)  What are the alternatives to the main intervention? No handwashing
O Outcome Any specific outcomes or effects of your intervention. Reduced infection

Richardson, W.S., Wilson, M.C, Nishikawa, J. and Hayward, R.S.A. (1995) 'The well-built clinical question: a key to evidence-based decisions.' ACP Journal Club, 123(3) pp. A12

PEO is useful for qualitative research questions.


Example question: How does substance dependence addiction play a role in homelessness?

Population/Problem/Patient Who are the users - patients, family, practitioners or community being affected? What are the symptoms, condition, health status, age, gender, ethnicity? What is the setting e.g. acute care, community, mental health? homeless persons
Exposure Exposure to a condition or illness, a risk factor (e.g. smoking), screening, rehabilitation, service etc. drug and alcohol addiction services
Outcome Experiences, attitudes, feelings, improvement in condition, mobility, responsiveness to treatment, care, quality of life or daily living. reduced homelessness

Moola S, Munn Z, Sears K, Sfetcu R, Currie M, Lisy K, Tufanaru C, Qureshi R, Mattis P & Mu P. (2015) 'Conducting systematic reviews of association (etiology): The Joanna Briggs Institute's approach'. International Journal of Evidence-Based Healthcare, 13(3), pp. 163-9. Available at: 10.1097/XEB.0000000000000064.

PCC is useful for both qualitative and quantitative (mixed methods) topics, and is commonly used in scoping reviews.

Example question:  “What patient-led models of care are used to manage chronic disease in high income countries?"

Population "Important characteristics of participants, including age and other qualifying criteria.  You may not need to include this element unless your question focuses on a specific condition or cohort." N/A.  As our example considers chronic diseases broadly, not a specific condition/population - such as women with chronic obstructive pulmonary disorder.

"The core concept examined by the scoping review should be clearly articulated to guide the scope and breadth of the inquiry. This may include details that pertain to elements that would be detailed in a standard systematic review, such as the "interventions" and/or "phenomena of interest" and/or "outcomes".

Chronic disease

Patient-led care models

Context "May include... cultural factors such as geographic location and/or specific racial or gender-based interests. In some cases, context may also encompass details about the specific setting." High income countries

Peters MDJ, Godfrey C, McInerney P, Munn Z, Tricco AC, Khalil, H. Chapter 11: Scoping Reviews (2020 version). In: Aromataris E, Munn Z (Editors). JBI Manual for Evidence Synthesis, JBI, 2020. Available from .

A model useful for qualitative and mixed method type research questions.

Example question: What are young parents’ experiences of attending antenatal education? (Cooke et al., 2012)

S Sample The group you are focusing on. Young parents
P of I Phenomenon of interest  The behaviour or experience your research is examining. Experience of antenatal classes
D Design How the research will be carried out? Interviews, questionnaires
E Evaluation What are the outcomes you are measuring? Experiences and views
R Research type What is the research type you are undertaking?  Qualitative

Cooke, A., Smith, D. and Booth, A. (2012) 'Beyond PICO: the SPIDER tool for qualitative evidence synthesis.' Qualitative Health Research, 22(10) pp. 1435-1443

A model useful for qualitative and mixed method type research questions. 

Example question: How effective is mindfulness used as a cognitive therapy in a counseling service in improving the attitudes of patients diagnosed with cancer?

S Setting The setting or the context Counseling service
P Population or perspective Which population or perspective will the research be conducted for/from Patients diagnosed with cancer
I Intervention The intervention been studied Mindfulness based cognitive therapy
C Comparison  Is there a comparison to be made? No  comparison
E Evaluation How well did the intervention work, what were the results? Assess patients attitudes to see if the intervention improved their quality of life

Example question taken from: Tate, KJ., Newbury-Birch, D., and McGeechan, GJ. (2018) ‘A systematic review of qualitative evidence of  cancer patients’ attitudes to mindfulness.’ European Journal of Cancer Care, 27(2) pp. 1 – 10.

A model useful for qualitative and mixed method type research questions, especially for question examining particular services or professions.

Example question: Cross service communication in supporting adults with learning difficulties

E Expectation Purpose of the study - what are you trying to achieve? How communication can be improved between services to create better care
C Client group Which group are you focusing on? Adult with learning difficulties
L Location Where is that group based? Community
I Impact If your research is looking for service improvement, what is this and how is it being measured? Better support services for adults with learning difficulties through joined up, cross-service working
P Professionals What professional staff are involved? Community nurses, social workers, carers
S Service  Which service are you focusing on? Adult support services

You might find that your topic does not always fall into one of the models listed on this page. You can always modify a model to make it work for your topic, and either remove or incorporate additional elements.

The important thing is to ensure that you have a high quality question that can be separated into its component parts.