Lessons from the recent Journal Citation Report figures

Mid-June has always been a period of great hope or perhaps fear for editors of medical journals. This is the time of the year when new figures for impact factors are released from the ISI Web of Knowledge. However , most editors these days have a good insight into the development of this very much debated instrument for evaluation of a journal's relative importance for the distribution of scientific information. By consultations of the continuous updating of citation figures for each individual article of their journals in either Web of Science (Thompson & Reuter) or SCOPUS (Elsevier) it is possible to make fairly good estimates of the figures to come. It was therefore not a great surprise to us when the new impact factor figure this time had increased to a record high 0.733. This also means that we have now increased our impact figure for five consecutive years (Figure 1). Unfortunately, we are afraid that there will be a dip next year, since the direct link to our home page at PubMed has been insufficient for almost a year. That has now been corrected in parallel with the connection of our journal to PubMed Central. This is an instrument for everyone to have free electronic access to all articles, in the case of UJMS from 1973 and onwards. Hopefully, this will mean that our figure for 'total cites per year' will increase from this year's 259, which was almost identical to that of last year (262). The figures of this year's Journal Citation Report reveal that our 'Immediacy index' (a measure of how often an article is cited during the publication year) has increased (from 0.067 to 0.083) and that figures for 'Cited half-life' (the median age of an UJMS article cited in 2009) and 'Citing half-life' (the median age of the items that UJMS cited in its 2009 articles) are well below 10 years. As mentioned above, an alternative database for information on the performance of medical journals is that of SCOPUS. Their SJR and SNIP figures are at present somewhat too unknown and vague to comment upon, but their figures for percentage of not cited papers in different journals are quite straight forward. In Figure 2 we have gathered data on percentages of articles not cited for UJMS and three other journals of interest—New England Journal of Medicine (the 'dragon'), Acta Dermato-Venereologica (another Uppsala-based journal), and The …