Abstracts are a synopsis (usually 250 words or less) of the most important aspect of an article. They should be clear, concise, and complete enough for readers to have a reasonable understanding of the important portions of the article.1 Since they are the most commonly read part of an article, they must be accurate and avoid the three most common errors: differences in information presented in the abstract and in the body of the article, information given in the abstract that was not presented in the article, and conclusions presented in the abstract that are not supported by information in the abstract.2-4
There are basically three types of abstracts that are seen in the literature. The first two (descriptive and informational) are somewhat traditional; however, they do not convey as much information as structured abstracts. Structured abstracts were originally designed to convey more information, and have been in use since the 1980s. The type of abstract to be used depends on the type of information and the requirements of the particular place the work is being submitted or used.
In addition to writing an abstract, some journals ask that indexing terms be submitted. Whenever possible, Medical Subject Headings (MeSH) from the National Library of Medicine should be used for the indexing terms. Each of the abstracts will be discussed in more detail in the following sections.
A descriptive abstract, as its name implies, simply describes the information found in an article. Few specific details are given and it is primarily used in a review article. An example of this type of abstract is as follows:
Lists of references that should be available, depending on location of the drug information service, are presented. These lists are specific to community, hospital, long-term care facility, and academic sites. Included are general references, indexing and abstracting services, and journals. Specialty references that would be useful in specific circumstances are also presented. In addition, the equipment and software necessary to access the computerized resources is shown for the individual references.
Informational abstracts concisely summarize the factual information presented in a study. This type of abstract is more applicable to clinical studies.
Key points to include in an informational abstract:
Study design (e.g., double-blind, crossover)
Number of patients and other demographic aspects
An example of this type of abstract is as follows:
A double-blind, randomized comparison of the effects of drug X and drug Y was performed in patients with tsutsugamushi fever, in order to determine whether either drug was superior in efficacy or safety. Twenty patients received 10 mg of drug X three times a day for 15 days. Eighteen patients received 250 mg of drug Y twice a day for ...