ranking iranian biomedical research centers according to h-variants (g, m, a, r) in scopus and web of science

background: we conducted a comprehensive bibliometrics analysis to calculate the h, g, m, a and r indicators for all iranian biomedical research centers (ibrcs) from the output of isi web of science (wos) and scopus between 1991 and 2010. we compared the research performance of the research centers according to these indicators.   methods : this was a cross-sectional and descriptive-analytical study, conducted on 104 iranian biomedical research centers between august and september 2011. we collected our data through scopus and wos. pearson correlation coefficient between the scientometrics indicators was calculated using spss, version 16.   results : the mean values of all indicators were higher in scopus than in wos. drug applied research center of tabriz university of medical sciences had the highest number of publications in both wos and scopus databases. this research center along with royan institute received the highest number of citations in both scopus and wos, respectively. the highest correlation was seen between g and r (.998) in wos and between g and r (.990) in scopus. furthermore, the highest overlap of the 10 top ibrcs was between g and h in wos (100%) and between g-r (90%) and h-r (90%) in scopus.   conclusion : research centers affiliated to the top ranked iranian medical universities obtained a better position with respect to the studied scientometrics indicators. all aforementioned indicators are important for ranking bibliometrics studies as they refer to different attributes of scientific output and citation aspects.