Title and Abstract
1 How participants were allocated to interventions
(e.g., "random allocation", "randomized" or "randomly assigned").
Examples
- In title: "Smoking reduction with oral nicotine inhalers: double blind, randomized clinical trials of efficacy and safety …" (62)
- In abstract: "Design: Randomized, double-blind, placebo-controlled trial" (63)
Explanation
The ability to identify a relevant report in an electronic database depends to a large extent on how it was indexed. Indexers for the National Library of Medicine's database MEDLINE may not classify a report as an RCT if the authors do not explicitly report this information. To help ensure that a study is appropriately indexed as an RCT authors should state explicitly in the abstract of their report that the participants were randomly assigned to the comparison groups. Possible wordings include "participants were randomly assigned to ..."; "treatment was "randomized"; or "participants were assigned to interventions by using random allocation". We also strongly encourage the use of the word "randomized" in the title of the report, to permit instant identification.
In the mid 1990s, electronic searching of MEDLINE yielded only about half of all RCTs relevant to a topic (64). This deficiency has been remedied in part by the work of the Cochrane Collaboration, which by 1999 had identified almost 100,000 reports of trials that had not been indexed as such in MEDLINE. These reports have been reindexed (65). Adherence to this recommendation should improve the accuracy of indexing in the future.
We encourage the use of structured abstracts when a summary of the report is required. Structured abstracts provide readers with a series of headings pertaining to the design, conduct, and analysis of a trial; standardized information under each heading (66). Some studies have found that structured abstracts are of higher quality than the more traditional descriptive abstracts (67) and that they allow readers to find information more easily (68).
Page last edited: 17 July 2007
