*5.1.1 Types of clinical questions*


Here are some examples of clinical scenarios for each type of clinical question to illustrate how you can design clinical questions using PICO.

#### *5.1.2 PICO for therapy questions*

When using PICO to formulate a therapy question, P is the patient or disease, I is medications or specific procedural interventions, C is comparison intervention (or no treatment), and O is the outcome of interest such as disease or condition management.

**Scenario:** Your preceptor wants you to search for literature. She is interested in whether acetaminophen is better than ibuprofen in reducing fever in young children.

**PICO:** P = Young children, I = Acetaminophen, C = Ibuprofen, and O = Reduced fever.

**Clinical question:** Is acetaminophen more effective than ibuprofen in reducing fever in young children?

#### *5.1.3 PICO for diagnosis questions*

To formulate diagnostic questions using the PICO framework, P is the population of interest or the target disease, I is a diagnostic test or procedure, C is an alternative diagnostic test or the current gold standard test for the problem, and O is a measure of the test utility such as the sensitivity and specificity of the diagnostic tool, although the outcome measures usually do not need to be included in database searches.

**Scenario:** You are part of a team reviewing local cervical screening guidelines. The most commonly used test is the Pap test, which detects abnormal cells but does not detect the HPV virus. In recent years, tests have been developed to detect the HPV virus. You may want to know what the latest evidence says about using HPV and Pap tests, or whether they should be used in combination.

**PICO:** P = cervical cancer, I = HPV test, C = Pap test, O = effect of both tests.

**Clinical question:** Is the HPV test or Pap test more effective in detecting cervical cancer?

#### *5.1.4 PICO for prognosis questions*

When using PICO to generate prognostic questions, P is the patient, population, or problem; I is the prognostic factor; C is usually not applicable; and O is the outcome of interest (e.g., deaths and recurrence). Many prognosis questions require only population and outcome because they are more often related to a broader population than to subgroup comparisons.

**Scenario:** The father of a twenty years old schizophrenic is worried about his son's future health. He asks you about possible relapses.

**PICO:** P = 20-year-old man with schizophrenia, I = inapplicable, C = inapplicable, O = relapse.

**Clinical question:** What is the likelihood of relapse in a twenty years old schizophrenic man?

*Perspective Chapter: Evidence-Based Medicine – A New Approach for Medical… DOI: http://dx.doi.org/10.5772/intechopen.107298*

#### *5.1.5 PICO for etiology questions*

When using PICO to formulate an etiology question, P is the patient or population, I is exposure to certain conditions or risk behaviors, C means not being exposed to those conditions or hazardous behaviors, and O is the outcome of interest such as the development of a particular disease or condition.

**Scenario:** You have a 39-year-old patient who has experienced heavy bleeding for most of her life. After considering all other options, we discuss the possibility of cervical surgery as a solution, although one may wonder if her high blood pressure in the year after surgery increases her risk of severe myocardial infarction.

**PICO:** P = 39-year-old woman undergoing cervical surgery, I = high blood pressure, C = normal blood pressure, and O = increased risk of acute myocardial infarction.

**Clinical question:** Are hypertensive women at higher risk of developing acute myocardial infarction in the first year after cervical surgery compared to nonhypertensive women?

#### **5.2 Step 2: acquire the evidence**

The second step is to search for the best available evidence in the medical literature that provides an answer to the question. This step involves identifying the search terms, selecting resources to perform your search, and developing an effective search strategy.

#### *5.2.1 EBM pyramid: the evidence hierarchy*

The EBM pyramid is a diagram that helps you understand how to weigh different levels of evidence for clinical decisions. It allows you to take a top-down approach to identify the best available evidence, by first searching for the recent systematic review, and if it is not available, search for the next level of evidence to answer your question. EBM pyramid ranks study types based on the strength and accuracy of their research methods. **Figure 2** below shows the hierarchy of evidence or the EBM pyramid.

At the top of the pyramid is filtered evidence, which represents the strongest level of evidence such as systematic reviews, meta-analyses, and critical appraisals. At the bottom of the pyramid is unfiltered evidence, including randomized controlled trials, cohort studies, and case-controlled studies. You should seek the highest level of evidence available, but be aware that filtered evidence may not be relevant to your specific clinical question. If so, you need to move the pyramid down to find strong evidence that will solve your clinical question.

#### *5.2.2 Filtered resources*

Filtered resources critically assess the quality of the study and recommend its application in practice. A critical appraisal of individual articles has already been done for you, which will save a great deal of time. As the critical appraisal is completed, the filtered literature is suitable to use for clinical decision-making during care. In addition to saving time, filtered literature often provides more accurate answers than individual research studies. Examples of filtered sources include systematic reviews from the Cochrane Database of Systematic Reviews, TRIP Database, JAMA Evidence, BMJ Best Practices, UpToDate, DynaMed Plus, ACP Journal Club, and PubMed (Medline).

#### **Figure 2.**

*Hierarchy of evidence or EBM pyramid.*
