Reliable interpretation of the results of a controlled trial entails
setting its results in the context of similar research. A previous study showed
that most reports of controlled trials published in 5 general medical journals
in May 1997 were deficient in this respect. We assessed the extent to which
reports of controlled trials published in the same 5 journals discussed new
results in light of the totality of evidence from other controlled trials.
Assessment of the discussion sections in all 33 reports of randomized
trials published during May 2001 in Annals of Internal Medicine, BMJ, JAMA, The Lancet, and The New England Journal of Medicine.
Three reports appeared to have been the first published trials to address
the questions studied. In none of the remaining 30 reports were the results
of the new trial discussed in the context of an updated systematic review
of other trials. Although reference was made to relevant systematic reviews
in 3 of these 30 reports, there was no integration, quantitative or qualitative,
of the results of the new trials in an update of these reviews. In the remaining
27 reports, there was no evidence that any systematic attempt had been made
to set the new results in the context of previous trials.
Between 1997 and 2001, there was no evidence of progress in the proportion
of reports of trials published in general medical journals that discussed
the new results within the context of, or with reference to, up-to-date systematic
reviews of relevant evidence from other controlled trials.