In an online literature database, every article is tagged with a keyword which is called "subject heading" for indexing purposes. In PubMed, this is called Medical Subject Headings (MeSH). By searching using a MeSH term, you will get more relevant articles. Even articles that do not use your keyword may appear in the search results.

For example: If you search using the "infant" keyword, you may not get the article: "Needle length and incidence of local reactions to immunisation: Is there a real benefit for the child?" This is because the keyword "infant" is not used in the article but "child". However, if you search using "infant"[MeSH], you will get it as this article was tagged using the "infant" MeSH term.

Please watch this video to learn how to search for MeSH terms in PubMed.
 

Now, please search for the MeSH term for each of the PICO and write them in the box below.