The "top 50": a perspective on the BMJ drawn from the Science Citation Index.
Authors: B Dixon
Journal: BMJ (1990)

BrMedJ 1990;301:747-51 The emergence of modern epidemiology, the in? creasingly detailed study of drug side effects and metabolism, and the considerable individual influence of Sir Richard Doll are three themes to emerge from my study of the 50 British Medical Journal  that were cited more frequently than any others during 1945-89. The study also discloses some surprises in the list of individual  that have been heavily cited and whose impact thus reflects their unusual influence on other authors. In addition, the analysis provides striking confirmation of the BMJ's strength in clinic? ally oriented publications, as shown recently by Shaw in a paper that shows that 62% of the journal's most highly cited  cover clinical research, in contrast with 55% of those of the Lancet. ' Conceived by Eugene Garfield and published by his Institute for Scientific Information, which is based in Philadelphia, the Science Citation Index is primarily a tool for retrieving information. An author can use it to find out, for example, how many times and where a paper has been included as a reference in other authors' publications. But, as Garfield pointed out in 1955,2 citation counts also mirror an author's impact in the scholarly community. While a paper describing research with Nobel prize potential is soon attracting many citations a trivial or insignificant paper is usually ignored. Garfield has repeatedly pointed out that citation ratings must be interpreted carefully and that they should not be used simplistically to compare the quality of work by particular researchers, departments, or institutions. Despite these warnings administrators and funding bodies have become increasingly attached to citation analysis?especially during times of finan? cial stringency, when a quantitative measure seems to offer concrete guidance in allocating scarce funds. There are, of course, real caveats that need to be borne in mind in using scientometric data. Self citation, for example, can be used to boost an author's citation rating. Secondly, a paper that is demonstrably erroneous may be cited for that very reason. But such aberrations do not seem to cause important problems when the upper strata of heavily cited  are being considered. Likewise, some critics of citation analysis seem to believe that the development of techniques is an intellectually inferior pursuit to the evolution of new ideas and argue that citation counts give dispropor? tionate emphasis to  that differ little from popular new cookery recipes. In fact, investigational methods do have crucial roles in the advancement of science?another point illustrated by the study reported here. The box lists the top 50 papers that have been published in the BMJ in order of their citation counts as derived from the Science Citation Index for 1945-89. Also given is the average number of citations received by each paper a year. Clearly, both sets of figures need to be interpreted in relation to the amount of time that has elapsed since publication, during which other authors could have cited a particular paper.