Orthopaedic journals, impact factors, research impact and research quality

I am delighted to announce that Bone & Joint Research (BJR), which was only established in 2012, has now received its first impact factor, which is 1.640. This is the first opportunity that the BJR has had to get an impact factor, as a journal must be registered in PubMed for at least three years. The journal impact factor is an independent measure calculated by Thomson Reuters in Philadelphia, United States and only a subset of journals are considered to be of sufficient quality to be listed by Thomson Reuters for an impact factor. The impact factors range from under 1 to over 50 (e.g. New England Journal of Medicine 55.87). Unfortunately, orthopaedic journals have relatively low impact factors, which tend to be less than 5. In comparison, several other body systems have journals with far higher impact factors, for example, the neurological system (e.g. 11.1) have multiple journals with high impact factors. It is, therefore, worth reflecting as to why orthopaedic journals do not have higher impact factors. The impact factor for a journal in a given year is calculated by dividing the number of citations, in that year, to the source items published in that journal during the previous two years, by the number of citable articles in the preceding two years. For example, the journal impact factor for Year X = (Year X citations to Year (X-1) + Year (X-2) articles)/(no. of "citable" articles published in Year (X-1) + Year (X-2)). Thus, for a citation to count towards a journal's impact factor, it needs to be cited within two years of publication. There are a number of factors that affect the total number of citations. The citations can be distributed evenly between the articles published, or, they can be heavily weighted to a small number of articles, which have a very high number of citations. For instance, in 2005 a study in Nature reported that 89% of the citations in its journal came from only 25% of the articles published. 1 Haddad 2 has listed a number of other factors that affect the number of citations, which include the number of publications in a research field; the average number of references in a paper and the type of article – reviews tend to get more citations, and scientific articles tend only to cite scientific articles, whereas clinical papers cite both clinical and preclinical articles. In addition to …