Getting the Most From anAdvanced Search on Medline Using Dialog By Stacey Louise Richards
Before Beginning Your Search• To give your search direction and keep you focused have a clear idea of the clinical question you are trying to answer.• Identify the significant keywords.• Use a PICO grid to help you
The PICO GridIf you have to convert a patient’s condition or problem intoa clear clinical question, you may find a PICO grid useful. ELEMENT DESCRIPTION EXAMPLE P Patient/Pop/People Disease/Condition Characteristics of the patient/population e.g. Gender, age, ethnicity I Intervention What do you want to do with this patient (e.g. treat, diagnose, observe)? C Comparison What are the alternative intervention options (e.g. placebo, different drug, surgery)? O Outcome(s) What are the relevant outcomes (e.g. quality of life, costs, morbidity)?
The PICO grid cont….By filling in the blanks you can then use the conceptsidentified in the PICO grid to formulate an answerablequestion:Among/In ____________________ PDoes ____________________ IVersus ____________________ CAffect/Result in ________________OFor example:In a 72yr old woman with osteoarthritis of the knee doesCox-2 inhibitor use versus other NSAIDS result in lessGI bleeding and increased pain control?
Medical Subject Headings• Searching MEDLINE is most effectively done using Medical Subject Headings (MeSH). All articles are indexed and assigned a number of subject headings before being added to Medline. By using these terms to search the database you will retrieve a maximum number of relevant articles.• Using MeSH avoids some of the pitfalls of free text searching: – Synonyms – word endings – differences in spellings – Lay and medical terms
Medical Subject Headings Cont.• Type your keyword into the search box and ensure that the Thesaurus mapping box is ticked.
Medical Subject Headings Cont.• When you click search a list of subject headings will appear.• Choose one that best suits what you are looking for. If unsure use the scope notes to find the definition of the index term
Medical Subject Headings cont.To retrieve very specificinformation, concentrate on asingle subject heading, but if yourinterest is more general you maywish to include all the subjectheadings linked to your area ofinterest. Do this by clickingthe box in the Explode column.Click the box in the Major columnif you want to retrieve articles inwhich the topic is one of the majorissues under discussion in thepaper.
Medical Subject Headings cont.• Combining searches – when using MeSH combine searches using “OR, OR, And.”• Step 1 - Combine your search terms and their MeSH terms with “OR” first• Step 2 - Then combine your “OR’d” searches and any remaining search terms where MeSH wasn’t used with “AND”• Step 1 ensures that the maximum number of results are retrieved, by finding articles with your search term or the MeSH term• By using “AND” this brings all the searches together and retrieves the specific results that contain all of the search terms.
Further Limits • To get more specific results a search can be limited by using the limit options under the search box. Options include: Publication year; age; gender; language and document type.
Other Ways to Search• By using the drop down box after the search box you can:• Search for journal titles, authors or by date.• You can also select to search only abstracts, titles or the whole document.
Other Ways to Search Cont.• Free text – This involves searching without using Thesaurus Mapping. Keywords must be chosen with care and attention paid to things such as, synonyms, word endings and lay/medical terms. Not the best way to search as there is potential to miss relevant material.• Truncation – When free text searching the symbol $ can be added to keywords to find all variations of that word.
Key Points & Tips To Remember• When doing a free text search spelling is critical. MEDLINE will automatically search for alternative American or English spellings, and also plurals.• Beware when truncating that you may retrieve terms that are not relevant. e.g. for articles mentioning haemorrhage(s), haemorrhaging or haemorrhaged: don’t truncate as haemorrhag* as you may also find articles on haemorrhagic fever.• Dialog does not allow punctuation (except for $, ? and -, all of which have specific uses). Instead of Down’s syndrome, enter Down syndrome; instead of Epstein- Barr virus, enter Epstein Barr virus.
Key Points & Tips To Remember Cont.• If a number is part of your search phrase, e.g. type 2 diabetes, you must enter it as type ‘2’ diabetes, i.e. use single quote marks around the number, otherwise the 2 will be interpreted as a search set.• When searching for authors use Thesaurus Mapping to bring up a list of all authors of the same name or similar, it also shows initial or first names by typing (author surname-?)• If you find a record that is highly relevant, view the full record with index terms. Browsing these index headings may suggest further index terms that you could use. Index terms are also hyperlinked, so clicking on a term does a search for that term.
Remember• If you need any help with searching then always come and ask at the library.• Any questions?