Background:
The questions and decisions involved in medical research are becoming increasingly complex and require more complex evaluation and synthesis of existing evidence. These require novel and sophisticated methodological approaches in synthesising different types of data, in evaluating multidisciplinary and complex interventions, and in synthesising appropriate data for further analysis. Since July 2016, the Complex Reviews Support Unit (CRSU), funded by National Institute for Health Research (NIHR), has been providing support to UK Cochrane Review Groups with a view to extending analyses and making reviews more impactful.

Objectives:
We will describe how the CRSU has successfully collaborated with Review Groups across differing review types. Through sharing examples of case studies, we will highlight feasible approaches that can be adopted to better prioritise and to undertake reviews that address complex decision questions.

Description:
This workshop will present a number of case studies on work undertaken by the CRSU. We will jointly present examples of collaborations between the CRSU and Cochrane Review groups. During this workshop, we will:
1) provide examples of how network meta-analysis and approaches to diagnostic test accuracy reviews have been used to expand the remit of reviews;
2) demonstrate the utility of an easy-to-use online network meta-analysis app that has been developed by members of the CRSU and used in a recent Cochrane Stroke Review;
3) consider the role of network meta-analysis within a conceptual framework (e.g. for policy agenda setting), and discuss more broadly, examples of areas where network-meta analysis approaches would be of value;
4) discuss the use of meta-analysis to inform the sample size of future trials based on their ability to impact future meta-analyses in the area of fertility treatments with numerous trials being conducted simultaneously.
It is believed that many of the issues the above projects raised will be applicable in other contexts, and time will be given for questions and discussion around the potential for similar collaborations in the future.