Influence module


Overview

The iCite: Influence module is a powerful web application that provides a panel of bibliometric information for journal publications within a defined analysis group (where an analysis group can consist of a single article or a very large group of articles). The data produced by iCite: Influence can be downloaded as a customized report from the dashboard and could be used to understand the influence of articles within an analysis group. An example application for iCite might be to compare how the influence of a portfolio of articles compares to the remaining articles that arise from grants funded by the NIH.

The following data are produced using iCite: Influence:

  • Total number of articles within the analysis group (Total Pubs)
  • Mean number of articles published per year (Pubs/Year)
  • Number of citations for articles in the analysis group per year (Cites/Year): maximum, mean, standard error of the mean, and median
  • Relative Citation Ratio (RCR): maximum, mean, standard error of the mean, and median
  • Weighted RCR: the sum of the RCRs for the articles within the analysis group

The Relative Citation Ratio is a metric developed within the NIH Office of Portfolio Analysis (OPA) that represents a citation-based measure of scientific influence of one or more articles, described in detail in a publication. It is calculated as the cites/year of each paper, normalized to the citations per year received by NIH-funded papers in the same field and year. Fields are sampled for each article by using its co-citation network. 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.

iCite is presently limited to analyzing only articles that appear in PubMed; users either execute a PubMed query or upload the PubMed IDs for articles within the analysis group of interest. The citation database powering iCite is generated from a number of sources, including CrossRef, MedLine, PubMed Central, and Entrez. At present, only PubMed citations are included, so citations appearing from journals outside PubMed are not counted.

Please note about the most recent RCR values that the Relative Citation Ratio is not available for papers published 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. 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.


Analyzing publications with iCite: Influence

Once the data have been processed, two summaries appear on screen: a table with summary data, and graphs with a year-by-year breakdown.

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Metrics describing the set of selected papers that were uploaded are displayed in this table. The metrics given in the table are Total Pubs, Pubs/Year, Cites/Year, RCR and Weighted RCR. Total Pubs, Pubs/Year and Weighted RCR are given as single values, but for Cites/Year and RCR, the maximum, mean, Standard Error of the Mean (SEM), and median are all shown. Users can click on the column labels to see detailed descriptions of how these metrics are calculated. These are summary statistics for the whole group, but yearly breakdowns are shown for Total Pubs, Mean RCR, and Weighted RCR in the graphs below.

Below are the descriptions that are shown when users click on the column labels:

  • Total Pubs: Total publications that could be matched in the citation database.
  • Pubs/Year: Publications per year, starting from the year of the earliest publication.
  • Cites/Year: Citations per full calendar year after publication, through the end of our records. The displayed values are the max, the mean, the standard error of the mean (SEM), and the median (MED) of the papers in the group. For example, a paper published in June 2012 with 30 citations by the end of 2014 would have 30 citations / 2 full calendar years (2013 and 2014) = 15 cites/year.
  • RCR: Relative Citation Ratio represents a citation-based measure of scientific influence of one or more articles. It is calculated as the cites/year of each paper, normalized to the citations per year received by NIH-funded papers in the same field and year. A paper with an RCR of 1.0 has received the same number of cites/year as the average 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 displayed values are the max, the mean, the standard error of the mean (SEM), and the median (MED) of the papers in the group.
  • Weighted RCR: This is the sum of the RCRs in this portfolio. This weights the article count by influence relative to NIH-funded papers. A highly influential set of articles will have a higher Weighted RCR than Total Pubs, while a set of articles with below-average influence will have a lower Weighted RCR than Total Pubs.

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These histograms show:

  • (Left) a box-and-whisker chart of the article RCRs,
  • (Middle) the number of publications per year,
  • (Right) the sum of the RCR of those same articles in each publication year. This amounts to an influence-weighted article count for each year.

Basic selection options

There are some options for selecting and deselecting subsets of the data based on publication year or type.

The year field has dropdown menu filters, which can be used to select a specified year range. Filters set in this way can be cleared by clicking the "Clear filters" button.

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Check boxes above the article table allow users to include only research articles, clinical articles, or articles that have been cited by clinical articles, in their selection.

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Table customization

In the article-level table, there are further customization options. You can see the title, authors, journal, NIH Percentile and RCR of each paper:

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Users can select and deselect individual papers with the checkbox on the left (for example, deselecting a person's middle-author papers). In addition, whole years can be selected or deselected. Selecting all or deselecting all, by clicking the check box next to the "PMID" column header, can be used to reset the individual selections. Note that other filters that have been set will remain in place. Columns are sortable, which is done by clicking the columns header. Clicking on "Year" will sort by publication year, for example, and clicking on RCR will sort by RCR.


Navigating the citation network

Users can navigate the citation network by clicking the "Citing Papers" and "Referenced Papers" buttons. Clicking "Citing Papers" will open a new iCite page to view the papers that cited the ones in this analysis group, while clicking "Referenced Papers" will open a new iCite page to view the papers that were referenced by those in the analysis group.

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