| dc.description.abstract | Introduction
At an early point in the development of evidencebased
health care, its advocates came to realize that
the way evidence, particularly quantitative data, is
presented has a major bearing on how it is
interpreted and implemented. Thus, Fahey and
colleagues sent 182 health-care executives and nonexecutives
details of a hypothetical mammography
programme and a cardiac rehabilitation programme.'
They presented the same results of research evidence
in four different ways. Decisions on which programmes
to fund were significantly influenced by the way in
which data were presented. This and similar research
has helped to stimulate enthusiasm for the 'number
needed to treat' as an intuitive and clinically
meaningful measurement of treatment benefit.2
Does this original experience have implications
within evidence-based library and information
practice? Would librarians and information officers
make different decisions about everyday practices
if presented with data in a way that is different
than that to which they are accustomed?
Desperately seeking evidence?
Systematic reviews increasingly feature on the
agenda of the health librarian.3 Large numbers of
information specialists are employed as members
of multi-disciplinary research teams to support
systematic review activities. At the same time,
health librarians in general are expected to advise
on whether a published systematic review has taken
reasonable steps to identify all relevant evidence. Of
course, 'reasonable' is a subjective concept that
is difficult to quantify. Certainly, early held preconceptions
suggested that such searches should be
exhaustive, if not in the strict sense of interrogating
multiple data sources, then in the resultant physical
and mental state of the hard-working information
specialist!
More recent developments within health technology
assessment have led to recognition that it is
not always possible (or indeed desirable) to expend
considerable resources in the pursuit of diminishing
returns from the evidence+ Time and funding for
systematic searching is usually finite. In many cases,
'good enough' is regarded as an acceptable substitute
for the ideal. Here again, 'good enough' is both
subjective and elusive.
Current controversies
Not everyone subscribes to the notion of 'good
enough'. The well-publici sed incident at John
Hopkins University is used by some to emphasize
the importance of exhaustive searching.' Just as
some clinicians refuse to acknowledge the concept
of 'medical futility' (i.e. a point at which therapy
should not be performed because available data
show that it will not improve the patient's medical
conditionj.e so some librarians will not recognize
'bibliographic futility' (i.e. a point at which further
literature searching should not be performed
because available data show that it will not affect
the overall result of retrieval).
There is also a need for agreement on what is a
worthwhile outcome. Librarians tend to focus on
'numbers of items retrieved', with the implicit
assumption that, if citations identified are topically
relevant, then they are worth finding. More important
for the review team, is the concept of 'appropriateness',
that is that the retrieved references are not
simply on the right topic but that they are also
eligible for inclusion in the review. Of course, such
a viewpoint is not only fundamentally pragmatic,
but can only be evaluated in retrospect-'was this
item of evidence included in the final review?' An
even less forgiving verdict would be 'did this item | en_US |
