Many readers will read only the abstract of your paper. For others, the abstract will induce them to read the paper in more detail. In either case, the abstract is VERY important. The purpose of the abstract is to make it easy for the reader to quickly grasp the key points of the article.2  However, writing it well may be a daunting task.1

Some general features of a good abstract

• It is succinct and tightly written. Keep it simple!
• It states clearly the hypothesis or objectives.
• It avoids unnecessary experimental details and statistical methods.
• It does not include references, tables or figures.
• It has few or no abbreviations.
• It states concisely and comprehensively the paper’s major findings in an easily understood manner.
• It has concise, clearly stated conclusion(s) linked to the hypothesis or objectives.
• It has good grammatical writing.

Observe the journal’s instructions for abstracts

• Structured vs unstructured format.
• If structured, use the recommended headings.
• Word limit
  • Journals may reject the article if word counts are exceeded.
  • Material that often can be eliminated without compromising the important message of the research is:
  • Unnecessary citation of published work
  • Unnecessary methodological detail
  • Results unrelated to the study aims
  • Conclusions not directly related to the results
  • Unnecessary wordiness

• Restrictions on the use of abbreviations
• Few or no abbreviations or acronyms may be permitted.

Structured vs unstructured abstracts

• Structured abstracts have become more common than unstructured abstracts.1, 2
• The most commonly used structure is the IMRAD (introduction, methods, results, and discussion) format.
• Structured abstracts make it easier for clinical readers and reviewers to identify the most important information.
• Structured abstracts are typically longer than traditional ones, but they may be more informative and accessible.3

Here is an example of an unstructured abstract and an edited, structured version of the abstract:

Unstructured abstract
Combining antibiotics with plant sterols that have antibacterial activity is a method of increasing the effectiveness of the antibiotics. In this study, we synthesized α-spinasterol from commercially available stigmasterol by a novel method in order to increase its yield, and tested the combination of the α-spinasterol with ceftiofur in vitro against four strains of pathogenic bacteria. The minimum inhibitory concentration (MIC) of stigmasterol, spinasterol and ceftiofur against Escherichia coli, Streptococcus pneumoniae CAU0070, Salmonella pullorum cvcc533 and Staphylococcus aureus were determined with a tube dilution method. Results showed that MICs of α-spinasterol against the four pathogenic microorganisms were the same for all (256 µg/ml), or one-half that of stigmasterol (512 µg/ml), and much greater than the MIC of ceftiofur (0.125 to 4 µg/ml). The combination of α-spinasterol and ceftiofur were strongly synergetic against the four bacterial strains; the fractional inhibitory concentrations on E. coli, S. pneumoniae CAU0070, S. pullorum cvcc533, and S. aureus were 0.375, 0.375, 0.533 and 0.5, respectively. In time-kill analyses, at concentrations above the MICs, ceftiofur exhibited only time-dependency against the four pathogenic microganisms, whereas ceftiofur in combination with α-spinasterol exhibited time-dependency and concentration-dependency. We conclude that ceftiofur combined with α-spinasterol, synthetized from stigmasterol by our method, is effective against four pathogenic bacterial strains in vitro. Effectiveness of this combination in vivo deserves investigation.

Abstract re-written in a structured format
Background/Aim. Combining antibiotics with plant sterols that have antibacterial activity is a method of increasing the effectiveness of the antibiotics. In this study, we synthesized α-spinasterol from commercially available stigmasterol by a novel method in order to increase its yield.
Methods. The minimum inhibitory concentration of stigmasterol, spinasterol and ceftiofur against Escherichia coli, Streptococcus pneumoniae CAU0070, Salmonella pullorum cvcc533 and Staphylococcus aureus were determined with a tube dilution method.
Results. Minimum inhibitory concentrations of α-spinasterol against the four pathogenic microorganisms were the same for all (256 µg/ml), or one-half that of stigmasterol (512 µg/ml), and much greater than the minimal inhibitory concentration of ceftiofur (0.125 to 4 µg/ml). The combination of α-spinasterol and ceftiofur were strongly synergetic against the four bacterial strains; the fractional inhibitory concentrations on E. coli, S. pneumoniae CAU0070, S. pullorum cvcc533, and S. aureus were 0.375, 0.375, 0.533 and 0.5, respectively. In time-kill analyses, at concentrations above the minimum inhibitory concentrations, ceftiofur exhibited only time-dependency against the four pathogenic microganisms, whereas ceftiofur in combination with α-spinasterol exhibited time-dependency and concentration-dependency.
Conclusions. Ceftiofur combined with α-spinasterol, synthetized from stigmasterol by our method, is effective against four pathogenic bacterial strains in vitro. Effectiveness of this combination in vivo deserves investigation.

Components of the structured abstract

• Introduction
• A brief background to the research
• Description of the study’s aims, why it was done, and what is important
• Methods
• Description of the study design and methodology, such as
• Retrospective case control study
• Randomized control study
• Results
• Concrete results related to the aim
• No results unrelated to the aim
• Real data, with confidence intervals and p values when appropriate1
• No ambiguous expressions, such as “relatively large” or “obvious difference”
• Conclusion(s)
• Direct linkage to the study aim
• Succinct statement(s) of what can be drawn from the study
• No exaggeration of the study’s importance or value
• Brief interpretation the results, implications and recommendations for further action

References

1. Ezeala, C. C. (2012). Writing a good abstract for a journal article. The 12th Pacific Islands Health Research Symposium. Sept 2012, Nadi Fiji. Cited on: May 5th, 2013. Available at: http://www.academia.edu/1950465

2. Nakayama T1, 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.

3. Hartley J. J Med Libr Assoc. Current findings from research on structured abstracts.2004 Jul;92(3):368-71.

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