Keywords:

Keywords enable the database searching of the article so To effectively conduct a search, keywords to be used in the search need to be identified, which are mainly the PICO elements. Moreover, a specific search Strategy using (AND, OR, and NOT) should be developed.

The search could be carried out by the different search engines. PubMed is a will-known search engine that accesses MEDLINE database for article and abstract in different life since including medicine. PubMed has many options for filtering which is very helpful for the researcher.

The main page includes a database selection menu, a search box, and an advanced search link.

• On the PubMed's homepage the database selection menu is displayed, Where the researcher can choose between PubMed and other NCBI databases.

• A search box appears where keywords are entered.

• Replace general search terms with more specific ones (e.g., low back pain instead of back pain).

• Include additional terms in your query.

• Use the sidebar filters to restrict results by publication date, full text availability, article type, and more.

  
  

2- Filters:

You can use filters to narrow your search results by article type, text availability, publication date, species, language, sex, subject, journal category, and age.

To apply a filter:

1. Run a search in PubMed.

2. Click the filter you would like to activate from the sidebar. A check mark will appear next to the activated filter(s). 

3. Subsequent searches will be filtered until the selected filters are turned off, or until your browser data is cleared.

The most popular filters are included on the sidebar by default. 

Combining search terms with Boolean operators (AND, OR, NOT)

PubMed applies an AND operator between concepts, e.g., "vitamin c common cold" is translated as vitamin c AND common cold. Enter Boolean operators in uppercase characters to combine or exclude search terms:

• AND retrieves results that include all the search terms.

• OR retrieves results that include at least one of the search terms.

• NOT excludes the retrieval of terms from your search.