MTV, sundhedstjenesteforskning og klinisk praksis

Some medical journals contribute to the distortion of research
priorities by prejudice against systematic reviews of research which
have revealed uncertainties about the effects of clinical practices.
The basis for publishing a systematic review should be whether the
question it addresses is important, not whether the research turns
out to produce “definitive evidence”.
The importance of taking account of what’s going on elsewhere
People planning and monitoring new research should also take account
of what is going on elsewhere. In addition to information
derived from systematic reviews, information contained in the increasing
number of registers of ongoing trials will help researchers
to decide whether or not to embark on new trials, and if so, how
to do so in a way likely to maximise the quality of the information
generated.
Sometimes, registered information about ongoing trials may lead
to a decision not to embark on another trial because it is judged
that answers to the questions being considered are likely to emerge
from work already in progress elsewhere. Sometimes information
about existing ongoing trials will prompt researchers to contribute
to them, both to reduce the infrastructure costs of the research
overall, and the time taken to achieve the sample size necessary to
obtain statistically robust estimates of effects.
Information about ongoing trials may also lead researchers to plan
collaborative analyses of similar, but independently organised
trials. Such prospectively planned meta-analyses using an agreed
core data set to address questions defined prior to inspecting the
data (12, 13) seem likely to offer an important way of generating
more precise estimates of treatment effects, as well as being a way
of confronting some of the practical and political problems faced
by those organising very large international controlled trials.
The principles described above apply not only to decisions about
whether to support new research, but also to decisions about
whether to continue supporting existing research. The dynamic
nature of accumulating evidence means that systematic reviews
need to be kept up-to-date, and that researchers, funding bodies
and data monitoring committees need to take account of changed
circumstances. Proposals for a large trial of thyrotropin releasing
hormone for anticipated preterm delivery were based on encoura-
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