Evidence-based medicine and statistics for O&G

The operational form is the five-step model, memorised in order — examiners will listen for the sequence:^[1]

1. Ask a focused clinical question (PICO).
2. Acquire the best available evidence efficiently.
3. Appraise the evidence for validity, results and applicability.
4. Apply the evidence to the patient, integrating expertise and values.
5. Assess the outcome and audit your decision. ^[1]

Asking the clinical question — PICO

Before you search, you must know what you are asking. A vague question returns an unmanageable pile of papers and an unfocused answer. The well-built clinical question has four parts, in order, every time:^[2]

• Population — who is the patient? Be specific (for example "nulliparous women at 36 weeks with a breech presentation, no contraindication to ECV").
• Intervention — what are you considering? (for example "external cephalic version at term").
• Comparator — what is the alternative? (for example "expectant management, awaiting spontaneous version or vaginal breech birth").
• Outcome — what matters to the patient? (for example "cephalic presentation at birth, successful vaginal birth, neonatal morbidity"). ^[2]

Two variants you may see: PICOS (S = study design — useful when you have a particular level in mind) and PICOT (T = time — useful for prognostic and follow-up questions). Don't argue the letters at the station — show you can frame the question, name the population precisely and decide what would change practice.^[2]