  National research impact indicators derived from citation counts are used by
governments to help assess their national research performance and to identify
the effect of funding or policy changes. Citation counts lag research by
several years, however, and so their information is somewhat out of date. Some
of this lag can be avoided by using readership counts from the social reference
sharing site Mendeley because these accumulate more quickly than citations.
This article introduces a method to calculate national research impact
indicators from Mendeley, using citation counts from older time periods to
partially compensate for international biases in Mendeley readership. A
refinement to accommodate recent national changes in Mendeley uptake makes
little difference, despite being theoretically more accurate. The Mendeley
patterns using the methods broadly reflect the results from similar
calculations with citations and seem to reflect impact trends about a year
earlier. Nevertheless, the reasons for the differences between the indicators
from the two data sources are unclear.
