Background: Pragmatic trials intend to guide users in choosing between options for care in a common environment and explanatory trials intend to test the causal relations in a research hypothesis. There are few trials that are purely pragmatic or explanatory. Objectives: To determine the position of trials from two Cochrane reviews within the pragmatic-explanatory continuum Methods: We selected the trials of two Cochrane reviews. One on mouthrinses for halitosis and the other one on interventions for oral submucous fibrosis (Fedorowicz 2008a, Fedorowicz 2008b) and assessed them using the pragmatic explanatory continuum indicator summary (PRECIS) tool (Thorpe 2009). Results: None of the studies were purely pragmatic or explanatory. They tended to be more explanatory than pragmatic especially in areas of flexibility of the experimental and comparison intervention, follow up intensity and more pragmatic in the selection of primary outcomes. There was insufficient information available to judge about the practitioner expertise in comparison and control group. Conclusion: The PRECIS tool is a useful tool in differentiating the pragmatic and explanatory aspects in a clinical trial. It can help clinicians in understanding the potential relevance of the results of the study for their future practice and systematic reviewers in providing practice and research recommendations.
References: Thorpe KE, Zwarenstein M, Oxman AD et al. A pragmatic-explanatory continuum indicator summary (PRECIS): a tool to help trial designers. CMAJ. 2009;180(10):E47 57.
Fedorowicz Z, Aljufairi H, Nasser M, Outhouse TL, Pedrazzi V. Mouthrinses for the treatment of halitosis. Cochrane Database of Systematic Reviews 2008a, Issue 4.
Fedorowicz Z, Chan Shih-Yen E, Dorri M, Nasser M, Newton T, Shi L. Interventions for themanagement of oral submucous fibrosis. Cochrane Database of Systematic Reviews 2008b, Issue 4.