Source dataset

The National Citation Report for Spain (NCR) database provided the bibliographical data and bibliometric indicators of all the publications in indexed journals reporting at least one address in Spain. Thomson-Reuters builds the NCR annually with data from the Web of Science (WOS) covering a period spanning from 1971 to 2012.

The number of citations to the publications compiled in the NCR was updated to the date the database was created, December 2012.

Classification of science

Documents (articles and reviews) indexed in the Web of Science (WOS), were classified according to Thomson-Reuters 250 categories (JCR disciplines), which depend on the journal where they are published. The JCR disciplines were subsequently classified into 22 fields, according to the Essential Science Indicators (ESI). Finally, the ESI fields were classified into 8 broad research areas: Clinical Medicine, Biology & Biochemistry, Pharmacology & Toxicology, Molecular Biology & Genetics, Neuroscience & Behavior, Microbiology, Immunology and Psychiatry/Psychology. These fields constitute the Biomedicine area considered for this study.

Citation percentile

The citation percentile indicates the position in which a given document falls in when compared with the rest of publications of the same type, JCR discipline and publication year in the WOS.

The position in which a document falls in the citation percentile changes in every computation of the indicator, as the number of citations increases with time. For this reason the number of citations required to become a Highly Cited Paper is higher for those documents published in 1997, than it is for those published in 2011.

Highly Cited Paper (HCP)

A Highly Cited Paper is any of the citable documents in the top 1% most cited publications in the world per document type and publication year. the 1997 HCPs on oncology are identified by comparing the number of citations (until 31-12-2012) to all the documents of the same type indexed in the Web of Science in this JCR discipline for 1997. If a document appears as a HCP in more than one category (JCR discipline), the present study shows the most favorable one.

Relative Highly Cited Paper (RHCP)

The RHCP is the ratio between the current number of highly cited papers and the total number of documents of the unit. A unit is defined as a territory or a research topic.
Values greater than 1 indicate that the unit is producing more HCP than the 1% expected according to the definition of the indicator.

Outstanding Papers (OP)

An Outstanding Paper is any of the citable documents in the top 1‰ (per thousand) most cited publications in the world per document type and publication year.

Sample size and characterization

The sample used in this study consisted of the list of authors of HCPs affiliated with at least one research organization in Spain. Subsequently, this list was normalized by disambiguating the publications mixed up in namesakes and unifying their variants. During this process the nicknames used by the authors to sign their publications were replaced for their full name.

Highlighted authorship roles

Authors occuring in the first and the last positions, as well as those reported as “correspondence author”, are thought to have played a leading role in the production of the HCP.

HCP reporting researchers affiliated with Spanish organizations in any of these positions were denoted as “leaded”.

Locating HCP on the map

Spain is integrated by 19 nations and regions (Autonomous Communities), which correspond to the second level of the Nomenclature of Units for Territorial Statistics (NUTS 2) of the European Union. The HCPs were located in Spain by associating the postal address of the authors’ host institution(s) to the city(ies) reported therein, giving full credit of the HCP to every different city. Thus, adding the number of HCP per CCAA will deliver a greater number of documents than the actual number of HCP included in the study, as a single HCP will be counted as many times as the number of different addresses reported that given HCP.

Performance of the JCR disciplines per ESI fields in the world

Number of citations to an average document in the biomedical JCR disciplines and publication year.