Background: Previous work by Elbourne et al. (2002) indicated that the description in the methods section of systematic reviews regarding how cross-over trial data were to be included was insufficient and recommendations were made for improvement. Recent work found that reports of cross-over trials often omit important methodological issues in design, presentation and analysis.

Objectives: To assess review methodology for including cross-over trials in reviews published by the Cochrane Cystic Fibrosis and Genetic Disorder (CFGD) Group and to investigate whether there has been an improvement compared to the Elbourne results published over 10 years ago. To assess the quality of reporting of cross-over trials within the trial reports themselves and subsequently, within Cochrane Reviews. To determine whether MECIR conduct and reporting standards for cross-over trials are adhered to.

Methods: CFGD reviews (published to September 2012) were accessed. Reviewswhich did not include cross-over trialswere excluded. The methods sections of reviews were checked to identify how review authors planned to manage cross-over trial data. Cross-over trial reports were accessed and the quality of the reporting of the results assessed and compared to the data included in the review by review authors.

Results: There were 104 published CFGD reviews, 82 (79%) included or planned to include cross-over trials; 39% of trials actually includedwere cross-over. However, 48% of reviewsmade no statement in their methods regarding including cross-over trials, or only referred to the work by Elbourne with no further details. Full results regarding the quality of reporting within the trial reports and how results were actually included in the reviews will be presented.

Conclusions: Guidelines are needed for reporting of cross-over trials. Review authors and groups should be more aware of the inclusion of cross-over trials within reviews and ensure the methodology is correct and data are included appropriately.