Structured abstracts: do they improve citation retrieval from dental journals?

To assess whether structured abstracts improved the sensitivity, precision and yield of retrieving clinical trials, using electronic searches, for example, MEDLINE, from dental journals.

Retrospective, observational study.

Clinical trials, published in six dental journals. Three that adopted structured abstracts (BDJ, CPJ, JO) and three that remained unchanged (JDR, EJO, AJODO) between January 1995 and December 1998 (extended to December 2002 for the JO).

Adoption of a structured abstract format.

Continued use of a non-structured abstract format.

A combination of handsearching and the Cochrane Collaboration Oral Health Group's Trials Register and/or CENTRAL were used to identify randomised controlled trials (RCTs) and controlled clinical trials (CCTs) over the selected time period. MEDLINE was used to identify clinical trials in the selected journals over the same time period.

There was no significant difference in the sensitivity or yield of clinical trial retrieval in journals with either abstract format over time. However, there was a significant increase in precision in journals that did not change their format (OR=4.96 (95% CI 1.18, 20.86) but not those that did. There was no significant difference in the sensitivity or yield of clinical trial retrieval either before or after the change in format or precision of retrieval before the change. However, in the later period, the precision of retrieval was significantly better in journals with unstructured abstracts compared to those with structured abstracts (OR=0.17 (95% CI 0.04, 0.7).

The use of a structured abstract format does not improve the sensitivity, precision or yield of retrieval of clinical trials from MEDLINE.