Respiratory System Research
Publication Analysis 2007-2013
by Kathleen Gransalke, Labtimes 03/2017
Chronic obstructive pulmonary disease is the discipline’s dominant topic. But it is not the one with the highest citation numbers.
SNSF, Lisa Conrad/ETH Zürich
February 27th, 2015 was a black day for all Start Trek fans. Leonard Nimoy, best known for playing the beloved character of Mr Spock, passed away from complications of COPD or chronic obstructive pulmonary disease. COPD is, as the name would suggest, not a specific disease but a collection of diseases, characterised by breathlessness, excessive sputum production and chronic cough. However, “COPD is not just simply a ‘smoker’s cough’ but an under-diagnosed, life threatening lung disease”, according to the WHO. In 2004, 64 million people had been diagnosed with COPD; for three million people COPD was the cause of death. The WHO predicts that by 2030, COPD will become the third leading cause of death worldwide.
COPD’s primary cause is smoking and also Mr Spock attributed his illness to this habit. On Twitter, he wrote one year before his death, “I quit smoking 30 yrs ago. Not soon enough. I have COPD. Grandpa says, quit now!!” Despite all sorts of scientific efforts, COPD is still not curable. It’s no surprise then that a majority of pulmonologists dedicate their time and workforce to this condition, making COPD, judged by our present publication analysis, one of the hottest topics in respiratory system research in Europe. Before we go into more detail, let’s have a more general look at the nations’ performance in this discipline. As with previous publication analyses, we relied, for this list, solely on so-called specialist journals, identified by the SciMago Journal & Country Rank and the Web of Science databases. Articles, reviews and proceedings papers published in multi-disciplinary journals, such as Nature, Cell or PNAS, were therefore omitted. The same restriction, however, did not apply to the most-cited authors’ ranking.
In Europe, as it turned out, England is the ne plus ultra in respiratory system research. With more than 100,000 citations of its 5,600 papers, the country leaves runner-up, Germany (77,000 total citations and 4,400 papers), far behind. Italy and France follow in second and third place, respectively. Scotland (11thth) and Poland (17th) also performed well, according to total citations. Focussing on average citations per article, however, Denmark (23.6) and Scotland (23.5) come off as winners.
On the global scale, European respiratory system researchers, once again, wrote more papers and gathered more citations than their US peers, but US pulmonology papers attracted, on average, two citations more (14.1 vs 16.1). Canada received a good average citation value, too (18.1), but is still far behind Europe’s best performers.
This brings us straight to the discipline’s top papers, which are often equatable to the field’s hottest topics. As already mentioned, chronic obstructive pulmonary disease is high on European pulmonologists’ research agenda. The third and fourth most-cited papers in respiratory system research, thus, deal with diagnosis, characterisation and treatment options of this group of diseases. Several of our top 30 most-cited authors participated in the research, on which these papers are based. On the remaining three spots, we make acquaintance with three other lung diseases: pulmonary arterial hypertension (high blood pressure caused by blocked arterioles and capillaries in the lung; 1st), pulmonary fibrosis (scarring of lung tissue; 2nd) and eosinophilic asthma (a subtype of asthma with increased numbers of eosinophils in blood, lung tissue and sputum; 5th). As with COPD, also these papers are about the conditions’ diagnosis and treatment options.
Now, it’s time to see who gathered enough citations to make our top 30 in European respiratory system research. But first, a few words about those who didn’t. As usual, we had to draw some delicate distinctions. Should we, for instance, include researchers studying lung cancer? We decided not to, as oncologists have their own ranking. How about allergologists? As we all know, some from personal experience, many allergies are attended by problems with the respiratory tract (think: hay fever). Again, we decided to leave them out as allergy research often goes hand-in-hand with immunology – and immunologists have their own ranking, too. Not included, either, are scientists from the public health sector, studying, for instance, the effects of air pollution on the respiratory system. We regarded this as too far away from our scope.
And thus, our publication analysis in respiratory system research in Europe is composed of not less than 13 researchers from the United Kingdom (five of them work at the National Heart and Lung Institute in London), five scientists from Germany, three each from France and Italy, two from Spain and The Netherlands (including the ranking’s only woman, Dirkje Postma, 7th, from the University of Groningen) and one scientist each from Belgium and Austria.
Although France has only three researchers among the top 30, two of them occupy the ranking’s leading positions: Marc Humbert on top spot, followed by Gerald Simmoneau in second place. The two work closely together at the University of Paris, on the already mentioned pulmonary hypertension. Humbert’s main aim is to decipher the condition’s pathophysiology, particularly he wants to understand “the cellular and molecular mechanisms of vascular remodelling in pulmonary arterial hypertension”. This knowledge will then directly benefit patients. Working at France’s National Reference Centre for Pulmonary Hypertension, Humbert wants “to translate novel information produced by our basic and clinical research units into advances for patient care”. Former head of the National Reference Centre, Gerald Simmoneau, is one of the field’s pioneers and contributed to the disease’s characterisation, epidemiology and treatment.
Research on pulmonary hypertension is obviously making an impact. Both papers on the subject and researchers studying it, lead our respective rankings. Not bad for a rare disease, affecting only six to seven thousand people in the UK. Humbert and Simmoneau are, however, not the only ones studying the disease. Among our top 30, five more scientists specialise in pulmonary hypertension: Nazzareno Galiè (6th), Marius Hoeper (12th), Hossein Ghofrani (21st), Walter Klepetko (24th) and Werner Seeger (27th).
As already implied, chronic obstructive pulmonary disease is of major interest for many pulmonologists in Europe. Quite a large number of our top 30 most-cited authors work, without taking a breather, on this subject. Often, COPD research is combined with studies on asthma. As a matter of fact, it was our ranking’s only woman, Dirkje Postma (7th), who unscrambled the COPD/asthma huddle and identified two separate diseases with differing clinical symptoms. Postma, who retired in 2016, is regarded by colleagues as the “most successful respiratory researcher in the Netherlands to date”. In addition to Postma, Peter Barnes (3rd), Alvar Agusti (5th), Jørgen Vestbo (8th), Emiel Wouthers (9th), David Lomas, (10th), Peter Calverley (13th), Paul Jones (16th), William MacNee (18th), Ian Pavord (22nd), Leonardo Fabbri (25th) and last but not least, Christopher Breitling (28th) seek to deepen our knowledge on the devastating lung disease.
A more clear focus on asthma throw Bart Lambrecht (15th), who unravels the cell biology of asthma, and Andrew Bush (23rd), who’s interested in characterisation and treatment of childhood asthma. Interstitial lung diseases, such as fibrosis and sarcoidosis, are the topic of interest for Andrew Nicholson (4th), Ulrich Costabel (17th), Athol Wells (19th) and David Hansell (26th).
Besides these “blockbuster topics”, a few top 30 respiratory system researchers are devoted to “niche subjects”, such as pneumonia (Tobias Welte, 11th and Antoni Torres, 30th) or the physiological basics and energetics of the airway smooth muscles (Kian Fan Chung, 20th).
Sifting through lung disease descriptions when compiling this publication analysis, we often came across two expressions: “not curable” and “causes are unknown”. For now, the only thing doctors can do is to treat the symptoms. But the respiratory system community is more than aware of the problem and has recently announced a ‘lung health research and medicine revolution’. As we hold our breath, patients can only hope this revolution will go through as planned.
View the Picture: Most Cited Authors
Last Changed: 28.06.2017