Without a well-focused question, it can be very difficult and time consuming to identify appropriate resources and search for relevant evidence. Practitioners of Evidence-Based Practice (EBP) often use a specialized framework, called PICO, to form the question and facilitate the literature search.1 PICO stands for:
|Framework item:||Think about:||Example:|
|Patient Problem (or Population)||What are the patient's demographics such as age, gender and ethnicity? Or what is the or problem type?||Work-related neck muscle pain|
|Intervention||What type of intervention is being considered? For example is this a medication of some type, or exercise, or rest?||Strength training of the painful muscle|
|Comparison or Control||Is there a camparison treatment to be considered? The comparison may be with another medication, another form of treatment such as exercise, or no treatment at all.||Rest|
|Outcome||What would be the desired effect you would like to see? What effects are not wanted? Are there any side effects involved with this form of testing or treatment?||Pain relief|
When forming your question using PICO, keep the following points in mind:
When forming your question using the PICO framework it is useful to think about what type of question it is you are asking, (therapy, prevention, diagnosis, prognosis, etiology). The table below illustrates ways in which Problems, Interventions, Comparisons and Outcomes vary according to the type (domain) of your question.2
|Question Type||Patient Problem or Population||Intervention or Exposure||Comparison or Control||Example Outcome Measures|
|Therapy (Treatment)||Patient's disease or condition.||A therapeutic measure, eg., medication, surgical intervention, or life style change.||Standard care, another intervention, or a placebo.||Mortality rate, number of days off work, pain, disability.|
|Prevention||Patient's risk factors and general health condition.||A preventive measure, e.g., A lifestyle change or medication.||Another preventative measure OR maybe not applicable.||Mortality rate, number of days off work, disease incidence.|
|Diagnosis||Specific disease or condition.||A diagnostic test or procedure.||Current "reference standard" or "gold standard" test for that disease or condition.||Measures of the test utility, i.e. sensitivity, specificity, odds ratio.|
|Duration and severity of main prognostic factor or clinical problem.||Usually time or "watchful waiting".||Usually not applicable.||Survival rates, mortality rates, rates of disease progression.|
|Etiology (Causation)||Patient's risk factors, current health disorders, or general health condition.||The intervention or exposure of interest. Includes an indication of the strength/dose of the risk factor and the duration of the exposure.||Usually not applicable.||Survival rates, mortality rates, rates of disease progression.|
Once you have clearly identified the main elements of your question using the PICO framework, it is easy to write your question statement. The following table provides some examples.
|Question Type||Patient Problem or Population||Intervention or Exposure||Comparison or Control||Outcome Measure|
|Therapy||In patients with osteoarthritis of the knee||is hydrotherapy more effective than||traditional physiotherapy||in relieving pain?|
|Prevention||For obese children||does the use of community recreation activities||compared to educational programs on lifestyle changes||
reduce the risk of diabetes mellitus?
|Diagnosis||For deep vein thrombosis||is D-dimer testing or||ultrasound||more accurate for diagnosis?|
|Prognosis||In healthy older women that suffer hip fractures||within the year after injury||what is the relative risk of death?|
|Etiology||Do adults||who binge drink||compared to those who do not binge drink||have higher mortality rates?|
1. Schardt, C., Adams, M. B., Owens, T., Keitz, S., & Fontelo, P. (2007). Utilization of the PICO framework to improve searching PubMed for clinical questions. BMC Medical Informatics and Decision Making, 7, 16. doi: http://dx.doi.org/10.1186/1472-6947-7-1
2. Fineout-Overholt, E., & Johnston, L. (2005). Teaching EBP: asking searchable, answerable clinical questions. Worldviews On Evidence-Based Nursing, 2, 157-160.