Searching for evidence Ann Winter November 2009

Nature of the topic Is there a standardised terminology around your topic? Is your topic uni/multi-disciplinary? Does your topic only have a local/national/world dimension? Are there influential authors or institutions in your topic area?

Amount of time Quick and dirty search limit to items in your library limit to core journals use methodological filters Slow but sure search follow up references to references include other languages include manual searching

How do you choose? Depends on the nature of the subject Depends on the databases you are using Depends on the amount of time you have Depends on how sure you want to be that you haven’t missed something

Reading browsing - flick through books and journals looking for anything of interest

Reading for improvement - look for answers to a specific question -focused searching Jones R and Kinmouth AL 1995 Critical reading for primary careOxford University Press.

Reading for research - gain a comprehensive view of existing state of knowledge, ignorance and uncertainty in a defined topic

Search techniques - 1 Snowball - find key article, look at references, look at references of references etc. until exhausted Citation cluster - keep adding new terms and phrases from cluster until all permutations are covered Citation thread - find early seminal work and look at all papers which cite it

Search techniques - 2 Key journal - identify the key journals for your topic and handsearch all the contents pages of each journal

Search techniques - 3 Index terms refers to a controlled vocabulary also referred to as MeSH (Medical Subject Headings) Frees you from having to consider different spellings or changing names e.g. diarrhoea vs diarrhea

Not want to miss anything Keep adding synonyms, spelling variants and related subject terms until subject is exhausted Check printed references in textbooks to see if your search has retrieved them Perform a citation search on key authors and works

Finding a particular paper that you know exists Access appropriate database Confidentiality and patients notes in BMJ 1. Confidentiality.ti - set 1 yields BMJ.jn - set 2 yields and 2 (Alt-C) yields 1 Or in 1 step confidentiality.ti and BMJ.jn

Useful search field suffixes (OVID).abin abstract.auauthor.jnjournal.tititle.twtitle or abstract.yrtear of publication 97.yr

Answering a specific clinical question MeSH MEdical Subject Headings 1. *anorexia nervosa/ - yield 750 * means major focus and /MeSH term 2. osteoporosis/ - yields oral contraceptives prompted to put contraceptives,oral/ - yields and 3 and 4 combines the sets or *anorexia nervosa/ and osteoporosis/ and contraceptives, oral/

Exploding terms ‘Diabetes mellitus’ might yield 5446 citations in Medline This was increased to 23,426 citations by exploding the term to include ‘like’ terms i.e. insulin dependent, non insulin dependent, diabetic neuropathies, ketoacidosis, diabetic nephropathies, coma’s, myocardial infarctions and obesity in diabetes The good news is that all possible relevant articles are included but the number is too large!

2 MAIN TYPES OF SEARCHING Trawling cast your net wide and spend all your time looking through your results Known as high sensitivity search All known publications Angling aim for a very specific concept and when this is exhausted move on to adjacent terms Known as high specificity search Very focussed

Useful resource Doing a literature review in health and social care : a practical guide Aveyard, Helen Book. English. Published Maidenhead : Open University Press 2007