PICO Question Examples: 15 Research Questions by Type (Plus PICOT, PECO and SPIDER)

PICO is the most common way to turn a vague research idea into a question that can be searched, screened and answered. It is standard in evidence-based medicine and systematic reviews, and works in many other fields too.

In short: a PICO question names the Population (who), the Intervention or exposure (what is done or experienced), the Comparison (the alternative) and the Outcome (what is measured). For example: "In adults with type 2 diabetes (P), does a structured walking programme (I) compared with usual care (C) reduce HbA1c (O)?" Add T for a time frame (PICOT), use PECO for exposures, and SPIDER for qualitative questions. You can draft and refine one with the PICO question tool.

What each PICO element means

The comparison can be left out when there is no meaningful alternative, for example in some prognosis questions.

15 PICO question examples by type

These examples are illustrative; adapt the population, outcome and wording to your own topic.

Therapy and intervention

1. In adults with type 2 diabetes, does a structured walking programme compared with usual care reduce HbA1c after 6 months?
2. In children aged 5–12 with acute otitis media, does delayed antibiotic prescribing compared with immediate prescribing increase symptom duration?
3. In postoperative patients, does early mobilisation within 24 hours compared with standard care reduce length of hospital stay?
4. In university students with exam anxiety, does a mindfulness app compared with a waitlist reduce anxiety scores over 8 weeks?

Diagnosis

1. In adults presenting with chest pain, is high-sensitivity troponin more accurate than standard troponin for ruling out heart attack?
2. In primary care patients with suspected depression, how accurate is the PHQ-9 compared with a structured clinical interview?

Prognosis

1. In patients who have had a stroke, does early depression predict lower functional independence at one year?
2. In preterm infants, is very low birth weight associated with developmental delay at age 5?

Harm and etiology

1. Are night-shift nurses more likely than day-shift nurses to develop sleep disorders?
2. In pregnant women, is exposure to air pollution associated with lower birth weight?

Prevention

1. In older adults, does annual influenza vaccination compared with no vaccination reduce hospital admissions for respiratory illness?
2. In secondary schools, does a sugar-sweetened beverage ban reduce student BMI over two years?

Beyond health

1. Education: In first-year university students, does weekly formative feedback compared with end-of-term feedback improve writing scores?
2. Environmental science: In urban areas, are green roofs compared with conventional roofs associated with lower indoor summer temperatures?
3. Qualitative (SPIDER): How do early-career nurses experience night shifts during their first year of practice?

Fill-in templates by question type

PICO variants: PICOT, PICOS, PECO, SPIDER and SPICE

• PICOT adds Time: the period over which the outcome is measured.
• PICOS adds Study design: useful for setting systematic review eligibility.
• PICOC adds Context: common in social science and information systems reviews.
• PECO swaps Intervention for Exposure: for observational and environmental questions.
• SPIDER (Sample, Phenomenon of Interest, Design, Evaluation, Research type) suits qualitative and mixed-methods questions.
• SPICE (Setting, Perspective, Intervention, Comparison, Evaluation) suits service and policy evaluation.

From PICO question to search string

Turn each element into a block of synonyms joined with OR, then join the blocks with AND. Outcomes are often left out of the search to avoid missing studies.

("type 2 diabetes" OR "diabetes mellitus, type 2"[MeSH]) AND (walking OR "physical activity" OR exercise) AND (HbA1c OR "glycated hemoglobin")

Then use the same PICO elements to write your inclusion and exclusion criteria and the headings of your data extraction form.

Using AI to draft PICO questions

AI can suggest PICO breakdowns of a broad topic and propose synonyms for each element. Ask it for several versions, then choose the one that is answerable and matters to your field. In this SciSpace rapid-review session, the presenter turns a research question into PICO with AI at 19:01; see also how to turn a research gap into a PICOT question at 17:24 in a researcher-led workflow session.

Key moments: 6:49 PICO research questions and screening criteria · 24:45 writing a good research question with the CORE prompt and PICO · 27:06 building a Boolean search string for Scopus.

Watch: PICO, PRISMA and Boolean search in one workflow

This SciSpace webinar shows how a PICO question becomes a Boolean search and then a PRISMA-reported literature review.

Related guides

Frequently asked questions

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