How to formulate a nursing research question is
easier to understand once you match the wording of the question to the
evidence you need. PICO is useful for intervention effectiveness, but it
is not the right framework for every nursing enquiry. Questions about
experiences, exposure, service context or the range of available
evidence require different structures.
This guide explains how UK nursing students can move from a broad
clinical concern to a precise, searchable and methodologically aligned
research question. It compares PICO, PIO, PEO, PICo, PCC and SPIDER,
provides worked nursing examples and shows how each framework affects
database searching and study selection.
Quick answer: To formulate a nursing research
question, define the population, identify exactly what you want to
examine, decide what kind of evidence could answer it and select a
framework that matches the question. Use PICO or PIO for interventions,
PEO for exposure and outcome, PICo or SPIDER for experiences, and PCC
for a scoping review.
Why the
research question controls the dissertation
A research question is not an administrative sentence added to a
proposal. It sets the boundaries of the project. It tells the reader who
or what will be studied, which relationship or phenomenon matters and
what kind of answer the dissertation seeks.
A clear question helps you:
- select a defensible research or review design;
- identify the main search concepts;
- write inclusion and exclusion criteria;
- choose relevant outcomes or experiences;
- avoid collecting evidence that does not answer the aim;
- maintain a coherent argument across the methodology, findings and
discussion; and - explain the value of the project to nursing practice.
An unclear question produces predictable problems. The search
retrieves thousands of loosely related papers, eligibility decisions
become inconsistent and the discussion drifts between several issues. A
well-built question prevents this by defining the intellectual job of
the dissertation before the main search begins.
The Cochrane
Handbook explains that a review PICO helps determine which studies
are eligible and how a synthesis will be structured. This connection
matters beyond Cochrane reviews: the concepts in the question should
remain visible in the search strategy, eligibility criteria, data
extraction and analysis.
How
to formulate a nursing research question in six steps
1.
Write the clinical or practice problem in plain language
Begin with the problem, not the acronym. Write two or three sentences
explaining what is happening, who is affected and why the uncertainty
matters.
For example:
Adults discharged after heart-failure admission must manage
medicines, symptoms and follow-up care at home. Readmission may occur
when discharge preparation is insufficient. It is uncertain whether
structured nurse-led discharge education improves outcomes compared with
routine information.
This statement contains a population, a nursing intervention, a
comparison and a possible outcome. It therefore points naturally towards
PICO.
By contrast:
Family carers of people with dementia often participate in hospital
discharge planning. Their experiences may reveal communication,
coordination and support needs that are not captured by readmission
data.
This problem concerns experience and context rather than intervention
effectiveness. Forcing it into PICO would weaken the question.
2. Decide what kind of
answer you need
Before selecting a framework, identify the question type.
| Question type | What you want to know | Likely framework |
|---|---|---|
| Intervention effectiveness | Whether one form of care improves an outcome | PICO or PIO |
| Exposure or risk | Whether an exposure is associated with an outcome | PEO |
| Experience or perception | How people experience or understand a phenomenon | PICo or SPIDER |
| Evidence mapping | What evidence exists and how it is distributed | PCC |
| Service or policy comparison | How an intervention or practice works across perspectives or settings |
SPICE |
The wording usually signals the question type. “How effective”,
“does” and “compared with” often indicate an intervention question.
“What are the experiences”, “how do people perceive” and “what barriers”
point towards qualitative enquiry. “What evidence exists” usually
indicates a scoping question.
3. Identify one primary
population
Specify the people, patients, carers or professionals to whom the
question applies. Avoid combining unrelated populations simply to make
the topic look broader.
Weak population:
Healthcare workers
Better population:
Newly qualified registered nurses working in UK adult acute-care
wards
Include only characteristics that affect relevance or eligibility.
Age, condition, nursing field, care setting and stage of treatment may
matter. Eye colour, marital status or an arbitrary narrow age band
probably will not.
4.
Define the intervention, exposure or phenomenon precisely
The central concept changes with the framework:
- Intervention: an action intended to produce change,
such as nurse-led education. - Exposure: a characteristic or event not assigned by
the researcher, such as night-shift work. - Phenomenon of interest: an experience, process or
issue, such as shared decision-making. - Concept: the broad subject mapped in a scoping
review, such as reasonable adjustments.
“Nursing care” is usually too vague. “A structured nurse-led
medicines-education session delivered before discharge” is more precise
and can be translated into search terms.
5.
Select outcomes or experiences that answer the problem
An outcome should represent the change that matters. Examples include
HbA1c, pain, readmission, medication adherence, pressure injury
incidence or quality of life.
Do not add every measurable outcome to one question. Choose a primary
outcome or a small, clinically coherent group. For qualitative
questions, the “answer” may concern experiences, perceptions, barriers,
acceptability or meaning rather than numerical change.
6. Test and refine the full
question
Read the question aloud and apply five tests:
- Clarity: Could another student explain what is
being investigated? - Focus: Does it contain one main enquiry?
- Answerability: Could available evidence genuinely
answer it? - Alignment: Does the wording match the proposed
methodology? - Feasibility: Can it be completed within the word
count, access and deadline?
Then perform a short database search. If the search produces
unmanageable results, narrow the population, phenomenon, context or
outcome. If it retrieves almost nothing, check synonyms and remove
unnecessary restrictions before abandoning the idea.
A weak question
corrected step by step
Weak question:
How does nursing affect diabetes?
First, define the population:
How does nursing affect adults with type 2 diabetes?
Next, replace “nursing” with a specific intervention and add an
outcome:
How does nurse-led self-management education affect glycaemic control
among adults with type 2 diabetes?
Finally, add the setting and comparator if they matter:
In adults with type 2 diabetes managed in primary care, how effective
is structured nurse-led self-management education, compared with usual
education, in improving HbA1c?
This progression shows how to formulate a nursing research question
by replacing vague terms with concepts that can guide eligibility
criteria and database searching.
PICO nursing research
questions
PICO stands for:
- P: Population, patient or problem
- I: Intervention
- C: Comparator or control
- O: Outcome
Cochrane
normally uses PICO for questions about the effects of interventions. It
is well suited to clinical trials, quantitative effectiveness reviews
and questions comparing two care approaches.
Worked PICO example
Broad topic:
Nurse-led education and type 2 diabetes
Framework:
| PICO element | Defined concept |
|---|---|
| Population | Adults with type 2 diabetes managed in primary care |
| Intervention | Structured nurse-led self-management education |
| Comparator | Usual diabetes education |
| Outcome | Glycaemic control measured using HbA1c |
Final question:
In adults with type 2 diabetes managed in primary care, how effective
is structured nurse-led self-management education, compared with usual
education, in improving HbA1c?
This question tells the researcher which studies are likely to be
relevant. It also indicates that a qualitative interview study alone
could not answer the effectiveness question.
When PICO is unsuitable
PICO becomes awkward when there is no intervention, comparator or
measurable outcome. A question such as “What are nurses’ experiences of
caring for people with dementia?” should not invent a comparison merely
to complete the acronym.
PICO also supports conceptual thinking, but copying every PICO phrase
directly into a database search may reduce retrieval. Eriksen and
Frandsen’s study found that PICO-based search blocks did not necessarily
produce better recall than simpler searches. Treat the framework as a
tool for defining the question and eligibility, then test the search
strategy rather than assuming that every element must be searched.
PIO nursing research
questions
PIO removes the comparator:
- P: Population or problem
- I: Intervention
- O: Outcome
It is useful when the question examines an intervention but no
meaningful alternative is required. This may occur in a single-group
project, an early review of an emerging practice or a question where
“usual care” is inconsistent.
Example:
| PIO element | Defined concept |
|---|---|
| Population | Hospitalised children undergoing venepuncture |
| Intervention | Nurse-led distraction techniques |
| Outcome | Procedural pain and anxiety |
Final question:
How do nurse-led distraction techniques affect pain and anxiety among
hospitalised children undergoing venepuncture?
PIO keeps the question concise, but removing the comparator changes
what can be concluded. If comparative effectiveness matters, PICO is
stronger. Do not remove “C” simply because the comparator is difficult
to describe.
PEO nursing research
questions
PEO commonly stands for:
- P: Population
- E: Exposure
- O: Outcome
Use PEO for questions about association, risk, cause or the
consequences of an exposure. The exposure is not an intervention
assigned to participants. Examples include shift work, workplace
violence, social isolation, medication exposure or living with a
long-term condition.
Worked PEO example
| PEO element | Defined concept |
|---|---|
| Population | Registered nurses working in acute hospitals |
| Exposure | Regular night-shift work |
| Outcome | Sleep quality and burnout |
Final question:
Among registered nurses working in acute hospitals, how is regular
night-shift work associated with sleep quality and burnout?
Some nursing resources also use PEO to organise qualitative
questions, interpreting the exposure broadly as an experience. This can
work, but the researcher must state how the framework is being used. If
the purpose is explicitly to explore lived experience, PICo or SPIDER
often communicates the qualitative orientation more clearly.
Do not confuse PEO with PIO. An intervention is deliberately
introduced to improve or change something; an exposure is a condition,
event or characteristic whose association with an outcome is
examined.
PICo nursing research
questions
PICo uses a lowercase “o” and should not be confused with PICO:
- P: Population
- I: Phenomenon of interest
- Co: Context
PICo suits qualitative questions concerning experience, perception,
meaning, communication or care processes. It replaces the quantitative
outcome with context, such as an acute ward, community service, care
home or particular cultural setting.
Worked PICo example
| PICo element | Defined concept |
|---|---|
| Population | Family carers of older adults with dementia |
| Interest | Experiences of discharge planning |
| Context | Acute hospitals |
Final question:
What are family carers’ experiences of discharge planning for older
adults with dementia in acute hospitals?
The question does not ask whether discharge planning “works”. It asks
how carers experience the process. Suitable evidence may therefore come
from interviews, focus groups, ethnography or qualitative components of
mixed-method studies.
PCC questions for scoping
reviews
PCC stands for:
- P: Population
- C: Concept
- C: Context
JBI recommends PCC when developing scoping-review titles, questions
and inclusion criteria. A scoping review maps the nature, range and
characteristics of evidence rather than answering a tightly specified
intervention-effectiveness question.
Worked PCC example
| PCC element | Defined concept |
|---|---|
| Population | Adults with learning disabilities |
| Concept | Reasonable adjustments supporting communication |
| Context | Emergency departments |
Final question:
What evidence exists on reasonable adjustments that support
communication for adults with learning disabilities in emergency
departments?
PCC is valuable when terminology, interventions or evidence types
vary substantially. It is not an excuse for an unlimited topic.
Population, concept and context still require explicit boundaries.
SPIDER
questions for qualitative and mixed-method evidence
Cooke, Smith and Booth developed SPIDER as an alternative search
framework for qualitative and mixed-method evidence synthesis:
- S: Sample
- PI: Phenomenon of interest
- D: Design
- E: Evaluation
- R: Research type
Worked SPIDER example
| SPIDER element | Defined concept |
|---|---|
| Sample | Newly qualified mental health nurses |
| Phenomenon of interest | Supporting people experiencing suicidal distress |
| Design | Interviews or focus groups |
| Evaluation | Experiences, confidence and perceived support needs |
| Research type | Qualitative or mixed methods |
Final question:
How do newly qualified mental health nurses experience supporting
people in suicidal distress in acute inpatient settings?
SPIDER can sharpen qualitative searching by making design and
research type explicit. However, Methley et al.
found a trade-off: SPIDER was more specific but less sensitive than PICO
in their comparison. In practical terms, it may retrieve fewer
irrelevant records but also miss relevant studies. Pilot both the
concepts and the search terms.
The final research question does not need to display all five SPIDER
elements. Design and research type can sit in the methodology and
eligibility criteria if including them in the question makes it
cumbersome.
How to
choose between PICO, PIO, PEO, PICo, PCC and SPIDER
Use the smallest framework that accurately represents the
enquiry.
| If your question asks… | Use | Typical opening |
|---|---|---|
| Does an intervention work compared with another approach? | PICO | “In…, how effective is…, compared with…, in improving…?” |
| Does an intervention affect an outcome without a comparator? | PIO | “How does… affect… among…?” |
| Is an exposure associated with an outcome? | PEO | “Among…, how is… associated with…?” |
| How do people experience a phenomenon in a setting? | PICo | “What are the experiences of… in…?” |
| What evidence exists about a broad concept? | PCC | “What evidence exists on… for… in…?” |
| Which qualitative or mixed-method evidence explores a phenomenon? |
SPIDER | “How do… experience or perceive…?” |
Do not choose the framework because it is the one most often
mentioned in lectures. Choose it because its elements match the logic of
the question.
Framework decision path
Use this quick sequence when deciding how to formulate a nursing
research question:
- Are you testing an intervention? Use PICO if
comparison matters, or PIO if it does not. - Are you examining a risk or exposure? Use PEO.
- Are you exploring experience or perception? Use
PICo for a concise question or SPIDER for a detailed qualitative
evidence search. - Are you mapping the range of evidence? Use
PCC. - Does the framework distort the question? Return to
the plain-language problem and select a better structure.
Turning a framework
into a database search
A framework identifies concepts. A search strategy translates those
concepts into database language. This distinction is essential when
learning how to formulate a nursing research question that is both clear
and searchable.
For the PICO diabetes example:
- List synonyms for the population: “type 2 diabetes”, T2DM, “diabetes
mellitus type 2”. - List intervention terms: “nurse-led education”, “diabetes
education”, “self-management education”. - Combine synonyms with
OR. - Combine separate concepts with
AND.
Example:
("type 2 diabetes" OR T2DM) AND ("nurse-led education" OR "self-management education")
The outcome may be omitted from the first search if including HbA1c
terms excludes useful studies. Comparators are also frequently poorly
reported in titles and abstracts. Searching is iterative: record each
version, inspect the results and justify the final strategy.
Use subject headings as well as keywords. In CINAHL these are CINAHL
Headings; in MEDLINE they are MeSH terms. Adapt syntax to each database
rather than copying one search string everywhere.
The nursing
dissertation literature review guide explains how to document
databases, search dates, limits and selection decisions after the
question has been finalised.
Common research-question
mistakes
Writing an aim instead of
a question
“To explore medication adherence” is an aim. Turn it into a question
by defining whose adherence, which medicine or condition, what aspect
will be explored and in which context.
Combining effectiveness
and experience
“Does nurse-led education improve HbA1c and what do patients feel
about it?” contains quantitative and qualitative enquiries. A
mixed-method study may address both, but the design, resources and
analysis must support two linked questions. Otherwise, select one
primary question.
Adding a comparator
that has no purpose
A weak PICO question sometimes compares an intervention with
“nothing” only to fill the C. Use PIO if no meaningful comparator
exists, but recognise the resulting limitation.
Treating frameworks as
search formulas
Not every element belongs in the final search string. Overloading a
search with population, intervention, comparator, outcome, design and
setting terms can exclude relevant studies.
Making the
population unnecessarily narrow
Every restriction requires a rationale. A question limited to nurses
aged 25 to 35 in one hospital may be impossible to support unless age
and location are central to the problem.
Using causal
language for non-causal evidence
An observational review may identify an association between night
work and burnout, but it may not prove that night work causes burnout.
Match verbs such as “affect”, “influence”, “associate” and “experience”
to the design.
Research-question quality
checklist
Before approval, confirm that the question:
- addresses one clear nursing problem;
- names a defined and defensible population;
- uses an intervention, exposure, phenomenon or concept
accurately; - includes a comparator only when comparison matters;
- specifies an outcome, experience or context appropriate to the
design; - can be translated into database concepts;
- has enough available evidence;
- aligns with the proposed review or research methodology;
- avoids causal claims the evidence cannot support;
- is feasible within the deadline and word count; and
- complies with ethics, governance and university requirements.
If two frameworks appear equally suitable, draft the question both
ways and run a short search. Compare relevance, volume and study types
before choosing.
Frequently asked questions
What
is the best framework for a nursing research question?
There is no universal best framework. PICO is strong for comparative
intervention questions, PIO for non-comparative interventions, PEO for
exposure and outcome, PICo or SPIDER for qualitative experience and PCC
for scoping reviews.
Can I use PICO
for a qualitative nursing study?
You can sometimes adapt PICO, but its intervention, comparator and
outcome structure often fits quantitative effectiveness better. PICo or
SPIDER may represent experience, perception and context more
naturally.
What is the
difference between PIO and PEO?
PIO examines an intervention and its outcome. PEO examines an
exposure and its relationship with an outcome. Nurse-led education is an
intervention; night-shift work is an exposure.
Does every PICO
question need a comparator?
If no meaningful comparison exists, use PIO. Do not invent a
comparator. If the dissertation aims to judge relative effectiveness,
however, the comparator should be retained and clearly defined.
Should
the complete framework appear in the dissertation title?
No. The title should communicate the topic, population and design
clearly without becoming cumbersome. Show the framework in the
question-development or methodology section.
Can the
framework change after the preliminary search?
Yes. Refinement is normal. A preliminary search may show that the
comparator is poorly defined, the population is too narrow or the
literature is mainly qualitative. Record and justify the change.
Conclusion
Knowing how to formulate a nursing research question means
understanding the logic of the enquiry before choosing an acronym. Begin
with the nursing problem, decide what kind of answer is needed and
define the population and central concept. PICO and PIO organise
intervention questions, PEO handles exposure and outcome, PICo and
SPIDER support qualitative enquiry, and PCC frames scoping reviews.
A framework improves clarity, but it cannot replace judgement. Test
the wording against the methodology, conduct a small scoping search and
refine the question until it is focused, searchable, ethical and
answerable.
If you have a promising topic but cannot decide which framework fits,
Nursing Dissertation Service can review the problem statement, compare
possible question structures and help you produce a defensible
question-and-method alignment for discussion with your supervisor. You
remain responsible for the final research decisions and your
university’s academic-integrity requirements.
