THE LANCET, AUGUST 2, 1986

ELECTRONIC PUBLICATIONS FOR

UPDATING CONTROLLED TRIAL REVIEWS

   SIR,-Many of your readers will have welcomed your decision to allow the results of the ISIS trial (July 12, p 57) to be presented within the context of a formal overview of all previously reported trials of early beta-blockade in acute myocardial infarction. Other reports of trials published by The Lancet1 would have been much strengthened had they included data derived from such overviews.2
   It is clear from a comment in your editorial accompanying the ISIS paper that you feel ambivalent about your decision to allow the inclusion of a "lengthy tailpiece". Your ambivalence probably reflects a concern that such reviews could take up an unacceptable amount of space in the journal. I can well understand that you might be reluctant to publish an overview as detailed as that in the ISIS paper next time you print a report of a trial of early beta-blockade in acute myocardial infarction. Even so I hope that you would accept a less lengthy tailpiece, showing how the results of the latest trial influenced the estimates of treatment effects derived from the ISIS overview.
   The updating of trial overviews as new information becomes available may be a task for which electronic publishing has something to offer. Next year the Oxford Database of Perinatal Trials3 will be published by Oxford University Press in electronic form. Besides registers of published4 and unpublished trials and trials in progress or planned, the data base will include a library of trial overviews which will be updated when new data become available.

Oxford Database of Perinatal Trials,
National Perinatal Epidemiology Unit,
Radcliffe Infirmary,
Oxford OX2 6HE

IAIN CHALMERS


1. Leveno KJ, Klein YR, Guzick DS, Young DC, Hankins GDV, Williams ML. Single-centre randomised trial of ritodrine hydrochloride for preterm labour. Lancet 1986; i:1293-96.
2. King JF, Keirse MJNC, Grant A, Chalmers I. Tocolysis-the case for and against. In: Beard RM, Sharp F, eds. Preterm labour and its consequences. Proceedings of the 13th Study Group of the RCOG. London: Royal College of Obstetricians and Gynaecologists, 1985: 199-208.
3. Chalmers I, Hetherington J, Newdick. M, et al. The Oxford database of perinatal trials: Developing a register of published reports of controlled. Controlled Clin Trials (in press).
4. National Perinatal Epidemiology Unit. A classified bibliography of controlled trials in perinatal medicine 1940-1984. Oxford: Oxford University Press, 1986.