Trends in RCT nursing research over 20 years: mind the gap.

Randomised controlled trial (RCT) literature plays a fundamental role in informing evidence-based medicine and nursing. This paper aims to track geographical and temporal trends in the publication of RCTs in nursing over the past 20 years by means of a bibliometric analysis. The PubMed database was searched for articles published from 1 January 1991 to 31 October 2011 and satisfying this search strategy: nursing [MeSH Terms] AND (RCT OR trial* OR 'experimental study' OR randomised OR randomisation) AND (English[lang]). Abstracts were reviewed to assess whether they met the criteria for an RCT. A manual search of information on country of origin was carried out and Journal Citation Reports® was used to allocate journals to subject areas. RCT methodology is increasingly drawing the attention of nursing researchers worldwide. However, there is a large disparity in research productivity, at least in terms of number of published RCTs in the English language and listed on PubMed, between the most productive continents, North America and Europe, and the others.