http://bmj.com/cgi/content/full/323/7320/1069/a
BMJ 2001;323:1069 ( 3 November )
Letters
Authors should make their data available
Hutchon discussed the desirability of
publishing the raw data used in medical research articles, and Eysenbach and
Sa have outlined some of the difficulties. 1 2 The
least that should happen at the moment is that authors should be
able to make their data available on a journal's website. One
journal that already does this is Clinical Chemistry, which
will include data supplements in the material sent to reviewers.3
Journals should encourage authors to post their data on the website.
One area where there should be neither debate nor difficulty is that of
systematic reviews. Readers of the review ought to have access to
the numerical results of the primary studies being reviewed to allow
the analyses to be checked and for other analyses to be
investigated. Also, this enables readers to examine the actual
results rather than the authors' aggregation or summary; for example,
they can assess the variation in event rates across the studies,
without which an odds ratio is impossible to interpret.
We have each separately had the experience of authors of systematic reviews
published in the BMJ refusing to release these data, in one
case to enable the data to be used in an educational article. Such
obstruction is worrying and suggests that some suspicion is
appropriate where none had existed at the time of the request. Given
that in almost all cases the results will already be in the public
domain, we can see no valid excuse for not including the data in the
report or making them available electronically. The missed
opportunity is even clearer in those cases where an extended version
of a paper appears on the web page but the trial results are still
not given, although in this case the authors have made the data
available to us.4
The BMJ and other journals should insist that authors of systematic reviews
adhere to one of the key recommendations the QUOROM statementnamely, to present simple summary results for
each treatment group in each trial, for each primary outcome.5
Douglas G Altman
ICRF/NHS Centre for Statistics in Medicine, Institute of Health Sciences,
Oxford OX3 7LF altman@icrf.icnet.uk
Christopher Cates
Bushey, Hertfordshire WD2 2NN
|
1. |
Hutchon DJR. Infopoints: Publishing raw data and real time
statistical analysis on e-journals. BMJ 2001; 322: 530 |
|
2. |
Eysenbach G, Sa E-R. Code of conduct is needed for
publishing raw data. BMJ 2001; 323: 166 |
|
3. |
Clinical Chemistry. Information for authors. www.aacc.org/ccj/infoauth.stm
(accessed 20 July 2001). |
|
4. |
Tramèr MR, Carroll D, Campbell FA, Reynolds DJM, Moore RA,
McQuay HJ. Cannabinoids for control of chemotherapy induced nausea and
vomiting: quantitative systematic review. BMJ 2001; 323: 16 |
|
5. |
Moher D, Cook DJ, Eastwood S, Olkin I, Rennie D, Stroup D,
for the QUOROM Group. Improving the quality of reports of meta-analyses of
randomised controlled trials: the QUOROM statement. Lancet 1999; 354:
1896-1900 |
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