The type of question determines which search strategy is useful, and when you should formulate your question as a PICO question.
| Description | Example Questions | Search Strategy | |
| Background Question | Find foundational information about conditions, tests, or treatments |
What is hypodontia? What is the chemical makeup of dental wax? |
Consult a reference source - a dictionary, clinical summary source, textbook, prescriber's guide, MDS, etc. |
| Foreground Question | Find specific information about therapy and prevention, diagnosis, etiology and prognosis to directly inform clinical decision making |
Is chlorhexidine effective in geriatric patients for treating mouth ulcers? |
Use the principles of EBD to formulate a clinical question to identify and use evidence - create a PICO question. Search for the most useful forms of evidence for the specific type of question in respectable sources |
Source:
PICO is a framework commonly used in Evidence-Based Practice to structure foreground clinical questions. A PICO question includes the following 4 areas.
| P Patient / Population / Problem | Who are the relevant patients? What specific characteristics are important? Age, sex, geographic location, etc. |
| I Intervention / Impact / Indicator | What is the management strategy, diagnostic test, or exposure that you are interested in? |
| C Comparison or Control | Is there a comparison concept or control group that you would like to consider? Not all questions include this concept. |
| O Outcome | What are you trying to accomplish, measure, improve or affect? |
PICOT, sometimes written as PICO(T), is a similar framework that includes a fifth concept that you may also find useful.
| T Time | What time periods should be considered? Is there a specific time frame that is important? |
Clinicians using a PICO or PICOT question must also consider a final concept, Type. The Type is the category of clinical question being considered. Different types of questions are best answered by different types of research studies and evidence.
| Type | What category of clinical question is being asked? What does that indicate about which types of evidence will be strongest for answering it? |
PICO or PICOT Question Framework
In POPULATION, does INTERVENTION as compared to COMPARISON/CONTROL GROUP result in OUTCOME?
or
In POPULATION, does INTERVENTION as compared to COMPARISON/CONTROL GROUP result in OUTCOME within TIME?
PICO is a framework for structuring clinical foreground questions, but its components are not clinical question types themselves. The question Type determines what types of primary study design provides stronger or weaker evidence for a particular question.
Select a study design appropriate to the type of question being asked, and the level of existing knowledge.
| Clinical Question Type | Purpose | Preferred Study Design Type in Order of Strength |
| Etiology / Harm | Identify associations, risk factors and causes of a disease | Randomized control trial (RCT), cohort, case-control, cross-sectional |
| Diagnosis | Identify tests or methods that accurately detect a disease or condition | Prospective blind controlled trial comparison to gold standard |
| Therapy / Treatment | Identify effective interventions to treat a disease | RCT |
| Prevention | Identify effective interventions to prevent a disease | Cohort, case-control, case series |
| Prognosis | Predict the probable outcome of a disease, condition or treatment | Cohort, case-control, case series |
| Cost Analysis | Identify the cost and benefits of a health condition or treatment | Economic analysis |
| Identify tests or methods that accurately detect a disease or condition |
|
Are (is) _________ (I)_________(O) in diagnosing _________ (P) compared with_________(C)? or |
| Example: (Time is optional). Is proteomic analysis of Gingival Crevicular Fluid (I) more accurate (O) in diagnosing periodontal disease (P) compared with traditional methods (C)? |
| Search Keywords: proteomics, gingival crevicular fluid, periodontal disease, diagnosis |
| Identify associations, risk factors and causes of a disease |
|
Are ____ (P) who have _______ (I) at ___ (Increased/decreased) risk for/of_______ (O) compared with ______ (P) with/without ______ (C) over _____ (T)? or Are ______(P) who have ______(I) compared with those without _______(C) at ________ risk for/of _______ (O) over ________(T)? |
| Example: Are children (P) who have _cleft palate (I) at increased risk of_dental caries_ (O) compared with children (P) without cleft palate_ (C) before age six (T)? |
| Keywords: cleft palate, children, caries |
| Questions addressing the treatment of an illness or disability |
|
In _________ (P), how does _________ (I) compared to _________ (C) affect _________ (O) within_________ (T)? or |
| Example: (Time is optional). In adults over age 65 (P), how does flossing (I) compared to using an electric toothbrush (C) affect the development of periodontal disease (O) within_a period of ten years (T)? |
| Keywords: adults over age 65, flossing, electric toothbrush, periodontal disease |
| Identify effective interventions to prevent a disease |
|
For ________ (P) does the use of ______ (I) reduce the future risk of ________ (O) compared with _________ (C) at the time of _________(T)? |
| Example: (Time is optional). For patients undergoing orthodontic treatment (P) does the use of chlorhexidine (I) reduce the future risk of oral ulcers ( (O) compared with no use of chlorhexidine (C) ? |
| Keywords: orthodontic, canker sores or aphthous stomatitis or oral ulcer, chlorhexidine |
| Predict the probable outcome of a disease, condition or treatment |
|
Does __________ (I) influence ________ (O) in patients who have _______ (P) over ______ (T)? or |
| Example: In patients with periodontal disease (P), how does twice annual dental cleaning (I) compared to yearly dental cleaning (C) influence the progression of disease (O) over a period of a decade (T)? |
| Keywords: periodontal disease, dental cleaning, progression or prognosis |
| Identify effective interventions to treat a disease |
|
In _______(P), what is the effect of _______(I) on ______(O) compared with _______(C) within ________ (T)? |
| Example: (Time is optional) In children under two (P), what is the effect of dental screening (I) on rate of caries development (O) compared with children who are not screened before age two (C) within the first 10 years of life (T)? |
| Keywords: infants, young children, screening, caries |
| Identify the cost and benefits of a health condition or treatment |
|
In _______(P), is treatment with _______(I) more cost effective (O) compared with treatment with _______(C)? |
|
Example: (Time is optional) In patients over 80 with mild periodontal disease (P), is treatment with dental implants (I) more cost effective (O) compared with full dentures (C)? |
| Keywords: people over 80 years of age, dentures, dental implants, costs |