Open Access Research BMJ Open: first published as 10.1136/bmjopen-2017-018705 on 12 November 2017. Downloaded from National citation patterns of NEJM, The Lancet, JAMA and The BMJ in the lay press: a quantitative content analysis Gonzalo Casino,1 Roser Rius,2 Erik Cobo2 To cite: Casino G, Rius R, ABSTRACT Strengths and limitations of this study Cobo E. National citation Objectives To analyse the total number of newspaper patterns of NEJM, The Lancet, articles citing the four leading general medical journals ► This is the first study that analyses the citations of JAMA and The BMJ in the and to describe national citation patterns. lay press: a quantitative the four leading general medical journals in the lay Design Quantitative content analysis. content analysis. BMJ Open press. Setting/sample Full text of 22 general newspapers in 2017;0:e018705. doi:10.1136/ ► This study shows the existence of a national factor 14 countries over the period 2008–2015, collected from bmjopen-2017-018705 in science communication that needs to be further LexisNexis. The 14 countries have been categorised into monitored and analysed. ► Prepublication history for four regions: the USA, the UK, Western World (European ► Citation and correspondence analyses offer a new this paper is available online. countries other than the UK, and Australia, New Zealand To view these files, please visit way to quantify and monitor the media impact of and Canada) and Rest of the World (other countries). the journal online (http:// dx. doi. scientific journals. Main outcome measure Press citations of four medical org/ 10. 1136/ bmjopen- 2017- ► This study is observational and descriptive; thus, it journals (two American: NEJM and JAMA; and two British: 018705). does not allow direct inference of causality. The Lancet and The BMJ) in 22 newspapers. ► This study is limited in scope, since the 22 Received 15 July 2017 Results British and American newspapers cited some international newspapers from 14 countries as Revised 4 September 2017 of the four analysed medical journals about three times a well as the 4 journals from 2 countries are selected Accepted 14 September 2017 week in 2008–2015 (weekly mean 3.2 and 2.7 citations, according to their relevance; but they are not a respectively); the newspapers from other Western representative random sample of the enormous countries did so about once a week (weekly mean 1.1), diversity of the lay and scientific publications around and those from the Rest of the World cited them about the world. once a month (monthly mean 1.1). The New York Times cited above all other newspapers (weekly mean 4.7). The analysis showed the existence of three national citation http://bmjopen.bmj.com/ patterns in the daily press: American newspapers cited newspapers and that these press citations— mostly American journals (70.0% of citations), British the number of press articles in which the newspapers cited mostly British journals (86.5%) and the name of a specific medical journal is cited— rest of the analysed press cited more British journals than are also important for medical journals,1 since American ones. The Lancet was the most cited journal press citations increase the visibility of papers in the press of almost all Western countries outside the and boost the number of citations in scien- USA and the UK. Multivariate correspondence analysis tific journals.2–5 Therefore, they are an indi- confirmed the national patterns and showed that over 85% cation of relevance and influence, although on September 29, 2021 by guest. Protected copyright. of the citation data variability is retained in just one single in this case it is social rather than scientific. new variable: the national dimension. For these and other reasons, most leading Conclusion British and American newspapers are 6 the ones that cite the four analysed medical journals medical publications issue press releases. more often, showing a domestic preference for their Despite this relevance, citations in the lay respective national journals; non-British and non-American press have been studied very little, and only a newspapers show a common international citation pattern. few small-scale studies have counted the cita- tions of some medical journals in the press of a single country.1 7 Quantifying how often 1 Department of Communication, INTRODUCTION medical journals are mentioned in the lay Pompeu Fabra University, Barcelona, Spain Citations of medical journals by other jour- press would provide an estimate of the social 2Department of Statistics and nals included in the Journal Citation Reports impact and influence of those journals and an Operations Research, Universitat are critical for scientific publications. They indicator of the media’s coverage of biomed- Politecnica de Catalunya, are used to calculate the journal impact icine and how relevant medical journalism is Barcelona, Catalunya, Spain factor, which the academic community views in different newspapers and countries. With Correspondence to as a proxy for its scientific relevance and the first objective of answering these ques- Dr Gonzalo Casino; influence. It is important to remember that tions, we performed the first analysis of press gonzalo. casino@ upf. edu medical journals are also cited by general citations of the four leading general medical Casino G, et al. BMJ Open 2017;0:e018705. doi:10.1136/bmjopen-2017-018705 1 Open Access BMJ Open: first published as 10.1136/bmjopen-2017-018705 on 12 November 2017. Downloaded from journals in a set of selected newspapers from countries all RESULTS over the world. Of the 22 analysed newspapers, The New York Times is by A previous study showed that most of the authors of far the one that cited the four analysed medical journals original papers published in NEJM, The Lancet, JAMA more often (weekly mean of 4.7 citations in the period and The BMJ were more frequently affiliated to institu- 2008–2015). Overall, the British and American newspa- tions in the same country as the journal; one exception pers mentioned a journal on average two to three times a was The Lancet, which is the journal with the highest week (weekly mean of 3.2 and 2.7 citations, respectively); proportion of papers from a country other than the the newspapers from the Western World region did so journal.8 We hypothesise that both the nationality of the about once a week (weekly mean of 1.1 citations); and journal and the nationality of the authors who publish the newspapers from the Rest of the World region cited in that journal are related to the number of citations, a journal about once a month (monthly mean of 1.1 cita- and that it is possible to identify some national citation tions) (table 1 and figure 1). patterns in the international lay press. Thus, it may be The Lancet was the most cited journal in the lay press that American and British newspapers have a domestic of almost all analysed Western countries except the USA preference for American or British journals, while other (which favoured NEJM) and the UK and Australia (where newspapers cite The Lancet more, as this journal has been The BMJ ranked first). shown to publish more papers from non-American and The US newspapers cited mostly the US medical jour- non-British authors of medical research.8 Our second nals (2352 citations out of 3360, 70.0%), while the UK objective in collecting this citation data was to study the press cited almost exclusively British journals (3466 cita- relationships (‘correspondences’) between newspapers tions out of 4008, 86.5%). The remaining lay press that and journals (which journals are cited by which news- was analysed cited British journals rather more than papers) and to what extent these might be linked to American, by a ratio of 2 to 1 (3474 citations out of 5450, 63.7%) (figure 2). national patterns. The correspondence analysis performed with the citation data in table 1 provided a two-dimensional plot (figure 3), showing two new calculated orthogonal dimen- METHODS sions that maximise the information retained in terms of We selected the four journals with the highest number of relationships between rows (newspapers) and columns total cites from the 2015 Journal Citation Reports (JCR, (medical journals). In other words, the plot displays the Medicine, General and Internal): NEJM, The Lancet, JAMA relationships between newspapers and medical journals and The BMJ. We then used the LexisNexis database to according to citations data while creating new dimen- sions that independently retains the maximum possible search through the full text of 22 daily newspapers, information. http://bmjopen.bmj.com/ seeking any 2008–2015 citations to the four journals. The The plot (figure 3) retains 98.55% of all the citation data newspapers were selected according to four criteria; they variability in table 1: horizontal dimension 1, labelled as had to be written in English, Spanish, French, German or the national dimension, retains 85.42% in new coordinates Italian; considered a national quality newspaper; ranked while the vertical dimension 2 retains 13.13% variability. the highest in circulation in its country and included in British newspapers are closer to the British journals, The LexisNexis during the study period. The selected newspa- Lancet and The BMJ, while the same occurs with American pers are listed in table 1 and classified under four areas of newspapers and journals. The lay press from the Western the world: the USA, the UK, the Western World (Canada, World and the Rest of the World are represented around on September 29, 2021 by guest. Protected copyright. Australia, New Zealand and European countries other the centre of the plot. The new coordinates in dimension than the UK) and the Rest of the World.