finding
the evidence
Example:
The first step when looking for evidence is to formulate
the question which needs to be answered. Looking at the case
study described in the text, it would be whether or not Betaseron
/ Interferon will be beneficial for Mr Moretti.
After the formulation of the question follows the identification
of possible sources of information. For most
of the questions encountered in general practice, where a
swift response is required, the electronic information
sources with frequent updates will be the best.
These can be on computer disk, CD-ROM or Internet.
This does not, however, render paper sources of information
obsolete. It is just that the electronic media is much
more accessible, and well indexed, and most importantly is
much more up to date. With the internet
it is also possible to link to unlimited related and supplementary
sources of information.
You
may ask: "So I need evidence. Now tell me how and where
to find it?" You find the answer to this
question in the following section.
The
key aspect of providing evidence-based health care is keeping
tabs on the availability, scope as well as the quality
of any new resource(s) which might be directly pertinent to
your own professional practice.
However,
keeping up-to-date means reading journals and this can prove
to be very time-consuming. To be able to keep up to date with
the current research in e.g. Internal Medicine a clinician
will have to read approximately 17 articles a day, 365 days
a year. This is not always possible, but clinicians caring
for patients need information on what the best treatment for
a particular patient may be.
In
order to overcome this problem there are several secondary publications
available that provide summaries or abstracts of key articles
of importance to particular clinical practitioners.
Secondary
Journals:
These
journals publish structured abstracts of articles which have
been published in other journals. They also publish
clinical commentaries on specific articles.
These
publications make use of librarians to hand-search clinical
journals and, then using previously established subject matter
and methodological criteria, they select those clinical articles
which seem to be scientifically sound and of which the conclusions
should therefore be valid. Before publication the selected
articles are first screened by a panel of experts in the particular
field of the journal.
Examples
of such journals are the following
- ACP
Journal Club
- General Internists
- Evidence-Based
Medicine - A combined subset of ACPJC abstracts with others
from journals in general practice, surgery, obstetrics and
gynaecology, paediatrics and psychiatry.
Search
Strategy
Now
that the resource has been chosen the search strategy needs
to be designed.
This
is done by identifying the key concepts within the clinical
question. Using our case study it will be Multiple
Sclerosis and therapy or therapeutics.
These
secondary publications observe two basic principles in order
to make information useful to the user.
- They
use explicit criteria for seeking and selecting the studies
that will be featured. It is made very clear to the reader
which journals have been covered and how the articles
have been selected.
- They
try to report enough information about the methods
of the studies ed. This is to enable the reader to judge
for themselves the quality and applicability for a particular situation.
If
no secondary journal is available in a particular field, the
best is to make use of general journals and use the criteria
from a secondary journal to determine the yield of clinically important
articles.
By
looking for evidence to solve a particular clinical problem,
rather than by browsing through journals looking for new
evidence which you think you might need later a person will
learn much more.
Good
questions serve as the backbone of both the practice and the
teaching of EBM, and patients serve as the starting point
for both.
The
basic steps for acquiring the evidence to support a clinical
decision are appears in Fig 1.
Figure
1: The steps in acquiring evidence
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