Influence of study design on the citation patterns of Danish, medical research

A recent report has shown a discrepancy between citations to Danish research publications with international collaboration and without; with a higher citation rate to international publications. This discrepancy is particularly large for the university hospitals. A possible explanation is the use of different study designs in national publications than international. Therefore, this study investigates a potential connection between study designs and citation rates in Danish, medical research. Web of Science records of Danish, medical research from 2005-2008 are enriched with study design information from MEDLINE. Citations are item-mean-normalised with respect to publication year. Our data confirms previous findings of correspondence between citation rates and study designs, and we observe differences in the frequencies of study designs for national and international publications. Citation rates for national and international publications vary; international publications are cited 1.50 to 3.43 times more often than national publications, depending on study design. Our results indicate that differences in citation rates for national and international publications to some degree can be explained by differences in the study designs used.