Element: Abstract

English-language abstracts are as supplied by the publisher or taken directly from the published article. If the article does not have a published abstract, NLM does not create one. However, in the absence of a formally labeled abstract in the published article, text from a substantive "summary," "summary and conclusions," or "conclusions and summary" may be used. Any copyright information, if available, will be included here as well. Publishers have given NLM permission to use abstracts for which they claim copyright; NLM does not hold copyright on the abstracts in PubMed. Users should obtain an opinion from their legal counsel for any use they plan for the abstracts in the database.

Generally, there are no abstracts for records created before 1975. However, starting in April 2007 NLM began to add abstracts from articles in PubMed Central (PMC) to the equivalent MEDLINE/PubMed citation record if that record does not already contain an abstract. The abstracts are derived from the PMC scanning project which is digitizing the back issues of participating PMC journals. As a result, additional records published prior to 1975 will contain abstracts.

All abstracts are in English. Some records may contain OtherAbstract in addition to or instead of Abstract. Because data entry policies at NLM have changed over the years, abstract records may be truncated, in which case one of the following phrases may appear at the end of the text:

  • ABSTRACT TRUNCATED AT 250 WORDS
  • ABSTRACT TRUNCATED AT 400 WORDS
  • ABSTRACT TRUNCATED

Original policy on inclusion of abstracts set a limit of 250 words for acceptance. Effective January 1984, the word limit was expanded to 400 words for abstracts from articles 10 pages or more in length, or from articles in the core journals identified by the National Cancer Institute. Abstracts exceeding the 250- or 400-word limit were to be included in trucated form at the end of the sentence closest to the word limit. The maximum length of abstracts for records created between 2000 and 2016 was 10,000 characters. Abstracts are no longer truncated.

Structured abstracts, describing key aspects of the purpose, methods, and results in a consistent way, are published in some journals. The key aspects of structured abstracts are capitalized to stand out, e.g., BACKGROUND, OBJECTIVES, METHOD, etc. Structured abstracts were not truncated in the past, even if they surpassed the previous 250- or 400-word limit.

Content Model

( AbstractText+, CopyrightInformation? )

Contains:

May be contained in:

Examples

<Abstract>
    <AbstractText Label="CLINICAL CHARACTERISTICS">Hereditary coproporphyria (HCP)...</AbstractText>
    <AbstractText Label="DIAGNOSIS/TESTING">The most sensitive...</AbstractText>
    <AbstractText Label="MANAGEMENT">Treatment of ...</AbstractText>
    <AbstractText Label="GENETIC COUNSELING">HCP is inherited...</AbstractText>
    <CopyrightInformation>Copyright © 1993-2017, University of ...</CopyrightInformation>
</Abstract>

<Abstract>
    <AbstractText>A pressing challenge in the modern health care system is the gap between education and clinical practice. Emerging technologies have the potential to bridge this gap by creating the kind of team-based learning environments and clinical approaches...</AbstractText>
</Abstract>