*5.2.4 Building a search strategy*

There are many ways to find information using online resources. An overview of these strategies is provided below. However, note that each database you use handles these strategies differently.

**Boolean Operators (AND, OR, and NOT)**: Boolean operators allow you to combine search terms to identify records that contain matching words.

**AND**


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


*Adapted from the Dartmouth Biomedical Libraries: Evidence-Based Medicine Worksheets: http://www.dartmouth.edu/ biomed/services.htmld/EBP\_docs/clin\_question\_worksheet\_EXAMPLE.pdf*

#### **Table 1.**

*Type of clinical questions and the ideal type of study to answer the question.*

Example: Hip **AND** Fracture retrieve documents containing both hip and fracture. **OR**


Example: Renal **OR** Kidney retrieves documents that contain either renal or kidney or both renal and kidney.

#### **NOT**


Example: pig **NOT** guinea will return items containing only the term pig but eliminates items containing the 2nd term (guinea) or both terms.

**Nesting or parentheses:** Use parentheses to group your search terms and Boolean operators in the order in which you want to process them. Using the advanced search screen in the database is another way to group your words so that you can find more relevant documents on the topic you want. **Example:** (dental anxiety OR dental fear OR dental phobia) AND (music therapy OR music).

**Truncation and Wildcards**: Using truncation and wildcards is a shortcut strategy for retrieving records that contain a word variation. Truncation markers allow you to add individual word endings and spellings without listing them as search terms. For example, educat\* will retrieve documents that contain words such as education, educator, educating, educated, or educational. Wildcards are often used to find alternate spellings of a word, such as wom?n for woman or woman. Be careful when using truncation and wildcard symbols as different databases use different symbols. To determine which symbol to use in the database you are looking for, find the Help screen and look for information on wildcards, truncation, or word variation.

**Field search:** A field is a part of an electronic record of a database. Try narrowing or broadening your search by searching specific fields such as author, subject, title, or full text.

**Controlled vocabularies:** Few databases contain thesauruses, but some use subject headings. If the database you are using has either, it is worth checking how the topics are grouped and the database language used. A subject title search is more accurate than a keyword search.

#### **5.3 Step 3: appraise the evidence**

Once the evidence that answers the clinical question is identified, the next step is to evaluate the evidence for its validity/closeness to truth and applicability/clinical importance. Critical appraisal of each type of study requires answers to three basic questions, which are as follows:


There are standard questions that can be used to assess the validity and applicability of evidence. The questions that can be asked depend on the type of clinical question and the study method. To see examples of these questions, refer to the worksheet below (**Tables 2**–**5**).

#### **5.4 Step 4: apply the evidence**

If you find evidence that is valid, important, and generalizable to your patient, you need to decide how to apply the findings to your patient care. Applying the best evidence is undoubtedly the EBM step that requires the most skill. It is at this stage that you synthesize your medical expertise and outstanding scientific knowledge with the patient's specific values and circumstances to make a clinical decision: Before applying evidence from research to your patient, answer the questions listed in **Table 6**.

#### **5.5 Step 5: assess the outcome**

The final step is self-assessment of your performance in the EBM process. You should evaluate your application of research evidence, identify the effectiveness of the strategies you have applied, and examine whether you are able to provide a satisfactory result to the patient. Self-assessment of performance in EBM is the process of answering questions in **Table 7**.
