Contribution of Countries and International Collaboration in Clinical Pharmacology Research. A Cross-Sectional Bibliometric Study of Six Top Ranked Specialty Society Journals

Abstract

There are no bibliometrics analyses on articles published in clinical pharmacology journals. We aimed to determine the countries in which authors of original investigations or meta-analyses were based and their international collaboration. This is a cross-sectional study conducted in six journals linked to learned clinical pharmacology societies/associations. For each journal, we started with the June-2025 issue and searched backward for articles meeting the selection criteria until 100 were identified or the January-2024 issue was reached. To calculate the credit by country, we used the complete fractionalized counting (CFC) method for assessing authors' contribution considering only the country of the authors included in the byline. CFC awards 1 credit among all authors and countries. A total of 503 articles were included in the analysis: 100 from four journals and 79 and 24 from the other two. Investigators from 66 countries from all continents contributed as authors; 46 countries provided lead authors. All but one were multi-authored articles; 9% were authored by international teams (range among the six journals: 16%–41%). Of the 503 credits, top countries were the United States (99.14), China (76.14), Japan (31.65), Denmark (28.69) and the Netherlands (27.29). The 17 EU countries obtained 151.86 credits (30.2% of the total). Among the top 25 countries, only five were not high-income countries. This exploratory analysis showed that with limited international collaboration, the authors of these studies worked mainly in wealthy countries, except for China.