Quantification of scientific output in cardiovascular medicine: a perspective based on global data.
OBJECTIVE
We sought to explore whether global and regional scientific output in cardiovascular medicine is associated with economic variables and follows the same trend as medicine and as science overall.


RESULTS
We registered the number of documents, number of citations, citations per document and the h-index for the first 50 countries according to the h-index (a measure to evaluate both the productivity and impact of the publications) in cardiovascular medicine. Economic variables (gross domestic product [GDP] per capita, % expenditure of the GDP in research and development [R&D] and health) were obtained from the World Bank, the UNESCO, and the World Health Organization. In total, the scientific output in cardiology showed the same position as in medicine and science overall (mean difference vs. medicine -0.9±5.3º, p=0.25 vs. science -0.7±5.3º, p=0.39). We found significant correlations between the h-index and the % GDP expenditure in R&D (r=0.67, p<0.001), and the % GDP expenditure in health (r=0.71, p<0.0001). Overall, there was a 21.4% (interquartile range 3.7; 55.0) increase in the % GDP expenditure in R&D between 1996 and 2007. Emerging economies showed the larger growth in % GDP expenditure in health and R&D.


CONCLUSIONS
The global situation of scientific output in cardiovascular medicine is highly polarised and closely related to economic indicators. Emergent economies, with higher rates of GDP growth and increasingly larger expenditures for R&D and healthcare, are expected to show a visible escalation in the scientific global picture in the near future.
Otamendi Hospital, Buenos Aires, Argentina.
Gastón A
GA
Rodriguez-Granillo
Alfredo E
AE
Rodriguez
Nico
N
Bruining
José
J
Milei
Jiro
J
Aoki
Keiichi
K
Tsuchida
Raquel
R
del Valle-Fernández
Chourmouzios A
CA
Arampatzis
Andrew T L
AT
Ong
Pedro A
PA
Lemos
Francisco
F
Ayala
Hector M
HM
Garcia-Garcia
Francesco
F
Saia
Marco
M
Valgimigli
Evelyn
E
Regar
Eugene
E
McFadden
Giuseppe
G
Biondi-Zoccai
Ezequiel
E
Barbenza
Paul
P
Schoenhagen
Patrick W
PW
Serruys
D015706:Bibliometrics; D002318:Cardiovascular Diseases / Q000188:drug therapy*; D059066:Gross Domestic Product / Q000706:statistics & numerical data / Q000639:trends; D005102:Health Expenditures; D006801:Humans