Article Contents

Overview

RCR Percentiles

RCR Distribution

RCR Stability

Citation Metrics Comparisons

Interpreting RCR

Overview

The Relative Citation Ratio (RCR), presented in the Influence module, is a metric developed within the NIH Office of Portfolio Analysis (OPA). RCR represents the field- and time-normalized citation rate, and fields are defined for each article by using its co-citation network.

RCR is benchmarked to 1.0 for a typical (median) NIH-funded paper in the corresponding year of publication.  This benchmarking process ensures that a paper with an RCR of 1.0 has received the same number of cites/year as the median NIH-funded paper in its field, while a paper with an RCR of 2.0 has received twice as many cites/year as the median NIH-funded paper in its field. The methodology is described in detail in Hutchins et al., PLoS Biol. 2016;14(9):e1002541.*

Relative Citation Ratio is not available for papers published in the last fiscal year, since, in general, not enough time has passed for citation statistics to meaningfully accrue in that time frame. An exception is made for papers with 5 or more citations since publication, as these are deemed to be accruing citations quickly enough for reliable calculations.

RCRs for papers published in the previous two years are flagged as "provisional" to reflect that citation metrics for newer articles are not necessarily as stable as they are for older articles. The current year in the database increments with the NIH Fiscal Year every October. For example, in June 2019 (NIH Fiscal Year 2019), papers from 2018 receive provisional RCRs if they have 5 citations or more, and all papers from 2017 receive provisional RCRs. In October 2019 (the start of NIH Fiscal Year 2020), papers from 2019 receive provisional RCRs if they have 5 citations or more, and all papers from 2018 receive provisional RCRs.

*This publication used R01-funded publications as a benchmark. The current RCR uses all NIH-funded publications as a benchmark.

RCR Percentiles

Percentiles for NIH-Funded Publications

NIH-funded papers are the benchmark for RCR: Any paper with RCR 1.0 has an RCR higher than 50% of NIH-funded papers. Some other RCR percentiles for NIH-funded papers are shown below.

Percentiles for All Publications

The iCite database contains many papers that were not NIH-funded. RCR percentiles for the full iCite database are shown below.

RCR Distribution

The distribution of RCRs for publications with RCR greater than 0 is shown below, with the tail truncated at 5.

RCR Stability

Stability of RCR over time. (A-E) Change in RCR over time for individual NIH-funded articles published in 1991. Articles were assigned to quintiles based on their RCR values in the year after publication (1992); RCR in each subsequent year was calculated. For each quintile, 200 individual articles (gray lines) were chosen at random from the subset whose 1992 values were within 10% of the median, and the resulting plots are shown. All values are actual and unsmoothed. In (A) through (E), the red line shows the median for the respective quintile. (A) Top quintile; (B) Upper mid quintile; (C) Mid quintile; (D) Lower mid quintile; (E) Bottom quintile; (F) Median RCR in each of the five quintiles for all NIH-funded articles published in 1991.

Citation Metrics Comparisons

RCR differs from other citation metrics in a variety of ways. See the table below for more information. 

Interpreting RCR

For more information about how to interpret RCR scores presented on iCite, see here.