A few specific guidelines to consider in preparing either type of abstract follow:
▪ Consult the journal’s instructions for authors.
▪ Follow the journal’s specific sideheadings when preparing a structured abstract.
▪ Do not begin the abstract by repeating the title.
▪ Do not cite references.
▪ Provide absolute results for main outcome measures (eg, report incidence rates rather than reporting only relative risks). In addition, provide confidence intervals whenever possible (if not, provide P values) (see 20.1, Study Design and Statistics, The Manuscript: Presenting Study Design, Rationale, and Statistical Analysis).
▪ Include major terms and describe databases and study groups (related to the subject under discussion) in the abstract, since the abstract can be text-searched in many retrieval systems.
▪ Include the stated hypothesis, if applicable.
▪ Ensure that all concepts and data in the abstract are included in the text.
▪ Include the active moiety of a drug at first mention (see 15.4, Nomenclature, Drugs).
▪ Avoid proprietary names or manufacturers' names unless they are essential to the study (see 15.5, Nomenclature, Equipment, Devices, and Reagents).
▪ Spell out abbreviations at first mention.
▪ If an isotope is mentioned, spell out the name of the element when first used and provide the isotope number on the line (see 15.9, Nomenclature, Isotopes).
▪ Provide the dates of the study, or date ranges for studies and other data included in reviews.
▪ Verify the numbers provided in the abstract against those provided in the text and tables to ensure internal consistency.