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Overview - Interventional Questions
The types of questions we ask about interventional
radiology procedures are similar to those surgeons and physicians
ask (sometimes about the same procedures!). We can, therefore,
make use of the evidence pyramid.
Search Engines
Secondary Literature: A useful,
free, starting point is a search engine that is designed with
issues of evidence quality in mind. This is SUMSearch.
Search term entry follows PubMed principles (and you will
get some helpful hints before your search starts). The results
will be returned in a ‘league table’ of evidence
categories. It can be a very useful ‘filtered’ resource
to give quick access to ‘best current evidence’.
It includes the Cochrane database in its search.
Primary Literature: These search
engines can be classified as ‘raw’ or ‘filtered’,
‘free’ or ‘subscription-based.’ PubMed
is an example of a free site, largely used for ‘raw’
searching. This is analogous to older computing interfaces
such as DOS. It is very powerful, but getting good results
is dependent on a high level of operator skill. Ovid
have produced and excellent search engine that is accessed
by subscription. It is (with a little training) easier to
use than PubMed and results are very comprehensive. The ‘filtered’
type of search is analogous to newer computing interfaces
such as Windows. The program designers have done a lot of
the work for you and users with little experience can get
decent results when looking for current evidence. Examples
of this are the Clinical
Queries section of PubMed (free) and the Knowledge
Finder (subscription) site. Knowledge Finder is definitely
worth a look if you are getting too much irrelevant material
on your PubMed searches. Its designers have applied fuzzy
logic, concept mapping, ‘up-front’ limits and author
search options with an option for listing of retrieved articles
by relevance. It is the kind of site that most practicing
radiologists will find much more satisfactory for use than
PubMed. The drawback is that some constraints are placed on
the overall power of the search by this type of system.
The APPRAISE
section of this site describes the hierarchy of evidence within
individual retrievals are ranked.
When to use which search engine?
If seeking a comprehensive interventional
literature review, we will usually try SUMSearch,
Knowledge
Finder and Clinical
Queries for a spectrum of papers (with MeSH terms) and
then use this information to build a PICO question (see the
ASK section of this site) for use in PubMed
or OVID.
You can also search the higher levels
of the Evidence Pyramid by going to one of the sites listed
in the introductory information above (e.g Evidence
Based Medicine, Clinical
Evidence). The sites are not geared towards Interventional
Radiology.
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