Using PICO(M) or another standardized framework helps organize the parts of the question and identify key concepts. PICO:
—Sources: Guyatt, 2015, Melnyk & Fineout-Overholt, 2005; Straus, 2011.
The following table summarizes the types of quantitative questions as well as the associated study design(s) to answer the question. The sample question templates can be used as a starting point to frame the PICO question. Based on the research topic/clinical problem, the PICO template may need to be modified and may not include all components (Cullen, 2018; Health Evidence, 2009; Greenhalgh, 2019; Guyatt, 2015; McKibbon, 1999; Melnyk, 2005). The short article by Oxford Centre for Evidence-Based Medicine provides an overview on study design/methodology and a comparison of advantages and disadvantages, OCEBM Study Designs.
| Type | Focus and Question Template | Characteristics | Methodology |
|---|---|---|---|
| Therapy |
Determine the effect of therapy/intervention (i.e., drug treatment, surgical procedure, education) on outcome(s) (i.e., symptoms, function, costs, morbidity, etc.). In patients with type 2 diabetes (P), what is the effect of sitagliptin (I) on glycemic control (O) compared with placebo (C)? In ___________(P), what is the effect of __________(I) on __________(O) compared with __________(C)? |
Involves choosing or comparing treatments Often compares two drugs/therapies Largest volume of questions |
Meta-analyses Systematic Reviews Randomized Controlled Trials |
|
Prevention |
Identify risk factors that if adjusted can help reduce the chance of developing the disease. In elderly patients (P), what is the risk of pneumonia (O) in patients who receive the influenza vaccine (I) compared with elderly patients who are not vaccinated (C)? In ___________(P), what is the risk of __________(O) in __________(I) compared with __________(C)? |
Involves choosing or comparing treatments Often compares two drugs/therapies |
Meta-analyses Systematic Reviews Randomized Controlled Trials |
| Diagnosis |
Demonstrate whether a diagnostic test is valid and reliable, in order to confirm or exclude a diagnosis. In young children with middle ear effusion, is microtympanometry (I) more accurate compared to medical history and otoscopy (C) in diagnosing hearing loss (O)? In __________ with __________(P), are (is) __________(I) more accurate in diagnosing __________(O) compared with __________(C)? |
Involves choosing, confirming, and comparing diagnostic tests Concerned with sensitivity and specificity |
Meta-analyses Systematic Reviews Prospective blind comparison to gold standard diagnostic test Cross-sectional studies |
| Etiology/Harm |
Determine the effects of a potentially harmful agent on outcomes. Are patients with restless legs syndrome (P) who take dopamine agonists(I) at risk for compulsive gambling (O)? Are __________(P) who __________(I) at __________risk for/of __________(O) compared with __________ with/without __________(C)? |
Risk or causality are key concepts Questions about negative impact from an intervention or exposure |
Meta-analyses Systematic Reviews Cohort Studies Case Reports |
| Prognosis |
Estimate a patient’s clinical course over time and anticipate probable complications of the disorder In patients with no motor response (P) three days following a hypoxic coma after a cardiac arrest (I), what is the chance of good neurological recovery (O)? In __________ with __________(P), does __________(I) influence __________(O) versus __________(C)? |
Concerned with the anticipated clinical course of a disease Relapse, mortality, or survival rate can be key concepts |
Meta-analyses Systematic Reviews Cohort Studies Case Reports |
—Sources: Health Evidence, 2009; Guyatt, 2015; McKibbon, 1999; Wessel, 2019)