PubMed service: How to use it efficiently?

When using PubMed, there are several convenient ways of searching for the information you need:

• by keywords, terms – the easiest and quickest option;
• by word root – it displays the results of searching for cognate terms with different endings;
• by phrase – you can find sources by a whole phrase or by a single word in a phrase;
• by author – the system will find all papers by a particular author that have ever been included in the PubMed database;
• by journal title – when entering the journal title or its abbreviation into the search box, all articles of that publisher available in the system will be displayed;
• by subject headings – accurate search by thesaurus terms.

The search for materials by keywords is carried out after entering the desired term in the search box. If you do not specify in which section you wish to search for a term, the platform finds matches for a word in several indexes alternately:

1. MeSH Translation Table – medical subject headings. The service displays all documents where the keyword appears in headings and texts.
2. Journals Table – journals. If no match is found for subject headings, the database searches by names and abbreviations of journals.
3. Phrase List – phrases. In the absence of a specified term in the first two index bases, further search is made by matching the entries. In case of no record found for the whole phrase, the search will be carried out for each word separately.
4. Author Index. If the previous search methods yielded no result and the term is specified as a word with one or two letters after it, then, at the final stage, the database will search for matches using the author’s surname and initials.

If no matches are found in any of the four index bases the system will display a message ‘No items found’.

To activate the ‘Truncation’ function, i.e. searching by word root, it is necessary to enter the term root in the search box, followed by “*”. The platform will find all available words with the same root but different endings. This method works only for a single word, but finds no matches for phrases and does not take into account any queries in subject headings.

When searching for content by phrase, PubMed by default finds matches for whole phrases and individual words. If you need to find only the whole phrase it must be enclosed in inverted commas (“ ”).

If the author search is used, a number of peculiarities should be kept in mind:

• if you enter only a surname in the search box the system will find matches within the author index and other fields, i.e. it will find not only articles by this author but also all the documents where his/her surname is mentioned in the text;
• if a surname and a single initial are entered the search is carried out using the author index, and all matches for this query will be found, i.e. all authors with similar data and a different second initial;
• entering a surname and two initials is the most accurate way of searching – all the works of the desired author will be displayed.

On the other hand, not all of the published scholars give their initials when posting a publication. If you do not find a match for a surname and two initials, but you know for sure that the required articles are present in the database, then try searching by a surname and one initial.

When searching for an article by a foreign author, another difficulty may arise – when translating surnames and initials into English, different translators, and the authors themselves, may use different transliteration. To find the work of a particular scholar, enter several options of the surname and use the logical operator OR between them.

To find all papers from a particular journal indexed in MEDLINE, just enter its full title into the search box. If you do not know the exact title or wish to view several articles on a particular subject use the Journals Database. This database contains the information on all journals published in PubMed, with description. To access the journal database, click on Journals Database in the main search menu on the left. The search in this section is performed by full title, abbreviation, any fragment of a title, ISSN number. In addition, there is a search by word root.

To find a particular article in a selected journal, go back to the general PubMed search box by posting the journal title in the main database. To do this:

• tick the box next to the title of the journal you need;
• click the arrow to the right of the ‘Send to’ function;
• select ‘Search Box’ with OR from the list;
• press ‘Search РubМеd’; the system will automatically perform the search and display the results.

Searching for subject headings through the relevant database (MSH Database) makes it possible to find materials by precise queries limited to basic terms and also to select appropriate subheadings and examine the keyword usage hierarchy in the articles. To make a search, go to the ‘MeSH Database’ section through the main search screen and enter the term you are interested in. A window will open with a list of similar keywords matching the subject headings, for you to select from.

A list of subheadings will open in the desired category list, making it possible to view the subject of interest from different angles. You can limit your search to a single subheading or browse through the articles in several sections at once. To specify the search, there are two commands:

• ‘Restrict Search to Major Topic headings only’;
• ‘Do Not Explode this term’ – exclude the materials containing the terms subordinate to the main key.

Using the ‘Limits’ function, when searching by subject headings, will help to reduce the time spent on finding useful sources, since you can set the limits by date of publication, language, age of patients and other criteria.