Skip to Content
United States National Library of Medicine National Institutes of Health

Structured Abstracts

What are Structured Abstracts?

A structured abstract is an abstract with distinct, labeled sections (e.g., Introduction, Methods, Results, Discussion) for rapid comprehension (see Example 1).

Example 1:

Am J Infect Control. 2008 Mar;36(2):118-22.
Risk factors and mortality in patients with nosocomial staphylococcus aureus bacteremia.

Wang FD, Chen YY, Chen TL, Liu CY.
Section of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.

BACKGROUND: Infections due to methicillin-resistant Staphylococcus aureus have become increasingly common in hospitals worldwide. S aureus continues to be a cause of nosocomial bacteremia. METHODS: We analyzed the clinical significance (mortality) of MRSA and methicillin-susceptible S aureus bacteremia in a retrospective cohort study in a 2900-bed tertiary referral medical center. Survival and logistic regression analyses were used to determine the risk factors and prognostic factors of mortality. RESULTS: During the 15-year period, 1148 patients were diagnosed with nosocomial S aureus bacteremia. After controlling potential risk factors for MRSA bacteremia on logistic regression analysis, service, admission days prior to bacteremia, age, mechanical ventilator, and central venous catheter (CVC) were independent risk factors for MRSA. The crude mortality rate of S aureus bacteremia was 44.1%. The difference between the mortality rates of MRSA (49.8%) and MSSA bacteremia (27.6%) was 22.2% (P < .001). Upon logistic regression analysis, the mortality with MRSA bacteremia was revealed to be 1.78 times higher than MSSA (P < .001). The other predicted prognostic factors included age, neoplasms, duration of hospital stay after bacteremia, presence of mechanical ventilator, and use of CVC. CONCLUSIONS: Resistance to methicillin was an important independent prognostic factor forpatients with S aureus bacteremia.

PMID: 18313513 [PubMed - indexed for MEDLINE]

What Kinds of Structures are used?

Standardized formats for structured abstracts have been defined for original research studies, review articles and clinical practice guidelines (1,2). The IMRAD format (INTRODUCTION, METHODS, RESULTS, DISCUSSION), a defacto standard that reflects the process of scientific discovery (3), is commonly used as a structure for journal abstracts (4,5). The CONSORT (Consolidated Standards of Reporting Trials) Group has recently issued a new guideline for reporting randomized controlled trials (RCTs) in journal and conference abstracts by developing a minimum list of essential items that authors should consider when reporting the main results of a RCT in any journal or conference abstract. CONSORT for Abstracts recommends that abstracts relating to RCTs have a structured format (6).

Why Use Structured Abstracts?

Structured abstracts have several advantages for authors and readers. These formats were developed in the late 1980s and early 1990s to assist health professionals in selecting clinically relevant and methodologically valid journal articles. They also guide authors in summarizing the content of their manuscripts precisely, facilitate the peer-review process for manuscripts submitted for publication, and enhance computerized literature searching (1,2).

The National Library of Medicine (NLM) studied structured abstracts in MEDLINE® from 1989-1991 and published an article characterizing structured abstracts by examining the occurrence of structured abstracts; characteristics of MEDLINE records with structured abstracts; editorial policies of selected MEDLINE journals, and a random sample of structured abstracts (7). Plans are underway to update NLM research on structured abstracts in MEDLINE/PubMed®.

The International Committee of Medical Journal Editors (ICMJE, of which NLM is a sitting member), whose "Uniform Requirements for Manuscripts Submitted to Biomedical Journals" document provides general guidelines for the format of manuscripts submitted to journals, endorses the use of structured abstracts. ICMJE does acknowledge the format required for structured abstracts differs from journal to journal and that some journals use more than one structure (8).

NLM Formatting of Structured Abstracts

NLM uses all uppercase letters for the labels that appear in structured abstracts in MEDLINE/PubMed citations (see Example 1).


  1. Haynes RB, Mulrow CD, Huth EJ, Altman DG, Gardner MJ. More informative abstracts revisited. Ann Intern Med. 1990 Jul 1;113(1):69-76. Cited in PubMed; PMID: 2190518.

  2. Hayward RS, Wilson MC, Tunis SR, Bass EB, Rubin HR, Haynes RB. More informative abstracts of articles describing clinical practice guidelines. Ann Intern Med. 1993 May 1;118(9):731-7. Cited in PubMed; PMID: 8460861. Available from:

  3. Sollaci LB, Pereira MG. The introduction, methods, results, and discussion (IMRAD) structure: a fifty-year survey. J Med Libr Assoc. 2004 Jul;92(3):364-7. Cited in PubMed; PMID: 15243643. Available from:

  4. Nakayama T, Hirai N, Yamazaki S, Naito M. Adoption of structured abstracts by general medical journals and format for a structured abstract. J Med Libr Assoc. 2005 Apr;93(2):237-42. Cited in PubMed; PMID: 15858627. Available from:

  5. Kulkarni H. Structured abstracts: still more. Ann Intern Med. 1996 Apr 1;124(7):695-6. Cited in PubMed; PMID: 8607606. Available from:

  6. Hopewell S, Clarke M, Moher D, Wager E, Middleton P, Altman DG, Schulz KF; CONSORT Group. CONSORT for reporting randomized controlled trials in journal and conference abstracts: explanation and elaboration. PLoS Med. 2008 Jan 22;5(1):e20. doi: 10.1371/journal.pmed.0050020. Cited in PubMed; PMID: 18215107.

  7. Harbourt AM, Knecht LS, and Humphreys BL. Structured abstracts in MEDLINE, 1989-1991. Bull Med Libr Assoc. 1995 Apr; 83(2):190-5. Cited in PubMed; PMID: 7599584. Available from:

  8. International Committee of Medical Journal Editors. Uniform Requirements for Manuscripts Submitted to Biomedical Journals: Writing and Editing for Biomedical Publication. [updated 2007 Oct; cited 2008 May 14]. Available from:

Last reviewed: 20 May 2008
Last updated: 20 May 2008
First published: 20 May 2008
Metadata| Permanence level: Permanence Not Guaranteed