Identification and analysis of randomised controlled trials in nursing: a preliminary study.

OBJECTIVES: To describe preliminary work undertaken for development of a nursing contribution to the Cochrane Collaboration. To ascertain whether there are randomised controlled trials (RCTs) on nursing care which need to be identified for inclusion in systematic reviews of the effects of health care. DESIGN: Searches by Medline (1966-94) and by hand of 11 nursing research journals from inception to the end of 1994 to identify RCTs and systematic reviews; and a comparison of searches by hand and by Medline for three nursing research journals. MAIN MEASURES: Total number of RCTs identified and number of RCTs published in nursing journals; the sensitivity of Medline searches; and aspects of nursing care evaluated by RCT. RESULTS: The work is ongoing and 522 reports of RCTs and 20 systematic reviews of effectiveness have been identified so far. The sensitivity of Medline searches for RCTs in nursing journals is as low as 36% for one journal and the lack of reference to research design in the title or abstract was the main reason for the lack of sensitivity. CONCLUSIONS: There are RCTs that evaluate aspects of nursing care, and are published in nursing and non-nursing journals, and are largely undertaken by nurses. These must be reviewed in ongoing systematic reviews of the effects of health care (including those undertaken as part of the Cochrane Collaboration). Nursing journals must be hand searched to identify these studies as the lack of reference to study design in the titles and abstracts of nursing trials leads to poor indexing in electronic databases such as Medline.