Tuesday, February 24, 2009

Searching PubMed & using subject headings

The previous posting dealt with checking how PubMed has interpreted the words you typed. A typical “translation” includes searching for those words (separately and as phrases) as well as a subject heading search.

But what are subject headings?

· Subject headings are added by indexers to the record when it is added to the database. The record describes the article: author, title, journal details, abstract and subject headings. The indexers read the article, identify the principal topics and add the standard subject headings to the record.

· They describe articles in a standardised way – eg, pressure sores, pressure ulcers, bed sores, bed ulcers are all described as decubitus ulcers

· Therefore a subject heading search for decubitus ulcers will pick up all the variations in the way the authors describe pressure sores, bed sores etc

· The words you type are translated into the appropriate subject heading. If you are unhappy with the subject heading, try a new search but describe the it in a different way

· PubMed explodes the subject heading: it searches for articles with the selected heading as well as articles with more specific headings on the same subject

· Click on the heading and you will see the tree (categories), which displays the narrower headings (more specific). For example, exploding Bereavement includes Grief in your search

· Use the MeSH Database in PubMed to carry out a subject heading search alone (ie excluding the word searches)

Use subject headings to:
· make your search more relevant – a subject heading will only be added if it is an important topic
· pick up the variations in describing the topic – the subject headings are standard
· gather narrower, related subjects into your search – when the subject heading is exploded

Be careful:
· In PubMed, the most recent articles don’t yet have subject headings, so you need to do word searches as well (default search)
· While subject headings are standardised, there can be differences in interpretation. For example, the topic “do not resuscitate” can be found with subject headings of “Resuscitation Orders”, “Refusal to Treat” and “ Withdrawal of Treatment”

More information on subject headings from the PubMed tutorial and the Information Seeking & Library Skills section on Moodle.

Tuesday, February 17, 2009

Do you know what PubMed is doing for you?

PubMed is an intuitive and sophisticated database. When you type in your keywords, it translates them into a complex search. You need to be sure that the system is interpreting them appropriately.

After each search, click on the DETAILS tab to find out.

You type deep vein thrombosis and PubMed translates it into the following searches:

Venous Thrombosis (MeSH – subject heading search)
venous and thrombosis (searches for the words, but not necessarily together or in that order)
“venous thrombosis” (searches for the phrase)
deep and vein and thrombosis (searches for the words, but not necessarily together or in that order)
“deep vein thrombosis” (search for the phrase)

Checking Details after each search allows you to keep track of the searches PubMed carries out on your behalf.

More information from PubMed or see the Information & Library Skills section on Moodle for lots of support material on searching PubMed.

Tuesday, February 10, 2009

New online pharmacopeias

The RCSI Library has new subscriptions to two online pharmacopeias

Martindale: The Complete Drug Reference is an extensive and well-referenced encyclopedia of facts about drugs and medicines aimed at researchers, medical professionals, pharmacists, and clinical education instructors.

Martindale contains:
Over 6,300 drug monographs
149,000 preparations
40,700 references
14,700 manufacturers
Synopses of treatments for more than 660 diseases
Enables identification of medicines, the local equivalent and the manufacturer
Includes herbals, diagnostic agents, radiopharmaceuticals, pharmaceutical excipients, toxins, and poisons as well as drugs and medicines
Based on published information and extensively referenced

Martindale is available on or off campus with your RCSI network username and password.

The British National Formulary (BNF) provides up-to-date information on prescribing, dispensing and administering medicines. It details medicines prescribed in the UK with special reference to their uses, cautions, contra-indications, side-effects, dosage and relative costs.

The BNF is published jointly by the BMJ Group and RPS Publishing and is updated every six months. It is intended for use by prescribers, pharmacists and other healthcare professionals.

BNF is available on or off campus with your RCSI network username and password.