Objective: The objective of this study was to elicit the factors related to worldwide variation in biomedical research productivity.
Methods: Biomedical research articles published in 1990-2000 were accessed through the MEDLINE database. The number of articles (journal articles) originating from each of the countries of the world was elicited and normalized to publication per million population per year.
Results: In a multiple regression model, where publication per million population was the dependent variable and 10 social and economic indicators were independent variables, gross national product (GNP) per capita and research and development (R&D) expenditure emerged as significant factors. In separate simple linear regression analyses, all but two independent variables were found significant.
Conclusions: To increase biomedical research output, GNP per capita and R&D expenditure are the most important factors to address.