Comparison of length limits and the actual length of abstracts in pharmacology, oncology, and neurology journals listed in PubMed

Purpose: This study aimed to compare the length limits specified in the author guidelines with the actual length of abstracts in 90 journals in the fields of pharmacology, oncology, and neurology. Specifically, the following parameters were examined: abstract formats among the three subject areas; the relationship between the length limit and the actual length of abstracts; and actual abstract length according to the number of subheadings, the length of structured abstract subheadings, the length of frequently used subheading sets, and clinical trial registration information. Methods: Thirty journals from each of three medical fields (pharmacology, oncology, and neurology) were selected from Elsevier’s Scimago Journal Rank. This included the journals indexed in PubMed from 2018 to 2019 that published the most articles. Article abstracts from these journals were used to create a dataset for this study. Descriptive, comparative, and correlational analyses of data for the three fields were conducted. Results: The number of subheadings and abstract length increased in parallel. The Results component was the longest, suggesting that authors tended to use longer text to report results than for other structural abstract components. Authors generally utilized the length limit to a full extent without exceeding it. Conclusion: The traditionally used 250-word length limit should be reconsidered for pharmacology, oncology, and neurology journals because it disregards the distinctive characteristics of abstracts and length differences between structured and unstructured abstracts. Various characteristics of abstract lengths presented in this study should be considered to establish more justifiable policies.