Estimates of global production in cardiovascular diseases research

Objective: To evaluate the contribution of different world regions in cardiovascular research production. Methods: The world was divided into 9 regions based on a combination of geographic, economic and scientific criteria. Using the Medline database, we retrieved articles from 77 journals included in the "Cardiac and Cardiovascular Systems" category of the "Journal Citation Reports" database for the period 1995-2002. We then, estimated the total number of publications, their mean impact factor, the product of these two parameters, the research productivity per billion of US dollars spent on research and development, and the research productivity per number of scientists-years in research and development for different world regions. Results: Data on the country of origin for the authors was available for 86,711 out of 87,939 retrieved articles (98.6%). The majority of articles published between 1995-2002 were originated from Western Europe (39.4%) and the USA (37.1%). The USA, Oceania and Canada had the highest mean impact factor of published articles and Eastern Europe had the lowest. The research productivity per unit of expenditure for research and development was found to be significantly higher for Canada compared to the USA and Western Europe while the rate of increase in the number of published articles was higher in Eastern Europe, Latin America and the Caribbean, and Asia. The research contribution of Africa in the number of published articles was notably very low (0.3%). Conclusions: The data suggest a promising trend: developing world regions, with the important exception of Africa, achieved a higher rate of increase in the number of published articles in the studied period.