There are a number of different kinds of metrics researchers, institutions and granting agencies use to try and measure the impact of research:
For more detailed information on the different types of research impact metrics and how to find them, check out the uOttawa's Scholarly Communication website.
Here at the Heart Institute, we track all of the publications produced by our researchers using monthly searches in PubMed and Scopus, and organized in Mendeley.
Want to do some serious number crunching with this data? Contact me for access to this information in other file formats (RIS, CSV).