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Evidence-Based Dentistry

Resources to support the practice of EBD

When to Use PICO : Background vs Foreground

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:

What is a PICO Question?

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 Framework

PICO or PICOT Question Framework 

  • Take note - Not every question will require every component.

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?

What are the Types of Clinical Questions?

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.

  • Take Note - Clinical guidelines based upon meta-analyses and systematic reviews, when available, often provide the best answers to clinical questions. Meta-analyses and systematic reviews include syntheses of results of multiple randomized control trial (RCT) or other high quality primary studies.

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

PICO Question Templates by Type

Diagnosis

Identify tests or methods that accurately detect a disease or condition

Are (is) _________ (I)_________(O) in diagnosing _________ (P) compared with_________(C)?

or
In _________(P) are/is _________(I) compared with _________(C) more accurate in diagnosing_________(O)?

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

 

Etiology

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

 

Intervention

Questions addressing the treatment of an illness or disability

In _________ (P), how does _________ (I) compared to _________ (C) affect _________ (O) within_________ (T)?

or
In _________ (P), what is the effect of _________ (I) on ______(O) compared with _________ (C) within _________ (T)?

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

 

Prevention

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

 

Prognosis/Prediction

Predict the probable outcome of a disease, condition or treatment

Does __________ (I) influence ________ (O) in patients who have _______ (P) over ______ (T)?

or
In _______ (P), how does ________ (I) compared to ________ (C) influence _________ (O) over _________ (T)?

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

 

Therapy

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

 

Cost Analysis

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

PICO Worksheets