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Dear all, On Wednesday 6th April, the RSS Leeds/Bradford local group will be hosting a series of talks on "design of clinical trials". The meeting will be held at Leeds University School of Mathematics on Level 8, Mathematics Active Learning Lab (MALL), starting at 2pm, with refreshments from 1.30pm in the level 9 foyer of the School of Mathematics. Dtails be found on our webpage: http://tinyurl.com/rss-lba ================================================================== Dr. Paul D. Baxter Secretary/Treasurer, RSS Leeds/Bradford Local Group, Division of Biostatistics, University of Leeds, Leeds, LS2 9JT, UK. ------------------------------------------------------------------- Leeds/Bradford: Wednesday 6 April, 2.00pm, University of Leeds. Design of clinical trials Clare Relton (University of Sheffield) Rethinking pragmatic clinical randomised controlled trial design The implementation and interpretation of both pragmatic and explanatory randomised controlled trials are associated with significant problems in the area of recruitment, patient preferences, ethics and treatment comparisons. This talk will describe a trial design that helps address these problems - the "cohort multiple randomised controlled trial" (cmRCT). The cmRCT design has several innovative features: a large observational cohort of patients is recruited and used as a multiple trials facility; each randomised controlled trial uses random selection of some participants (not random allocation of all); and "patient centred" information and consent is applied. I will discuss where the cmRCT design is best suited to, as well as address some of the analysis, implementation, and ethical questions related to the cmRCT design. Several examples of trials currently using this design will be provided. Ivana Holloway (University of Leeds) Design challenges for cluster randomised trials in stroke rehabilitation Cluster randomised trials (CRT) are practically and statistically the preferred design choice for stroke rehabilitation trials, when the intervention is delivered at service level, due to the contamination risk if patient-level randomisation is employed. Statistical issues encountered in the design and implementation of CRTs, illustrated by two UK trials: Training for Caregivers after Stroke (TRACS) and Longer-term Stroke Care (LoTS-Care) will be addressed. Patients are admitted to stroke units following their stroke, so necessarily cannot all be recruited at one time - the ideal design for a CRT. Hence, the design must minimise the potential for differential recruitment between randomised arms. Sample size calculation in CRTs requires estimation of the intracluster correlation coefficient (ICC) and cluster size. Maximum power is gained when cluster size is equal across all clusters. We will discuss methods employed to minimise cluster imbalance and consequent loss of power. We will also describe the randomisation method, which allows centres to be randomised in two waves. The successful implementation of both TRACS and LoTS-Care trials demonstrates that large multicentre CRTs in stroke rehabilitation are feasible, but issues regarding service provision for stroke patients should be addressed in the trial design. Helen Marshall (University of Leeds) Statistical issues in the design and analysis of randomised surgical trials: a practical example of the possible solutions Surgical randomised controlled trials have unique design and implementation issues which in turn bring many problems and issues to the analysis of such data. This presentation will describe the key problems encountered and the solutions adopted for the design and analysis of surgical trials performed at the CTRU. Alex Szubert (University of Leeds) Timing of randomisation in clinical trials: a review Although the timing of a randomisation in a clinical trial should be as close as logistically feasible to the point at which treatments diverge, the timing of that point may not be clear. For example, in haematological oncology there are trials of initial chemotherapy designed to eradicate or reduce disease followed by maintenance treatment intended to prolong the period where the disease is in remission. In some trials, patients are randomised between these initial chemotherapies then, once they have received chemotherapy, or achieved a sufficiently good response, they are randomised again between maintenance treatments. In others, they are randomised at the outset to receive a whole package, for example either (1) control chemotherapy and control maintenance treatment or (2) experimental chemotherapy and experimental maintenance treatment. Trials will be compared and contrasted. Other considerations with regard to the timing of randomisation will be outlined: 1. After vs. before baseline investigations; 2. Randomised vs. non-randomised phase II trials and; 3. Run-in periods. The meeting will be held at Leeds University School of Mathematics on Level 8, Mathematics Active Learning Lab (MALL), starting at 2pm, with refreshments from 1.30pm in the level 9 foyer of the School of Mathematics. You may leave the list at any time by sending the command SIGNOFF allstat to [log in to unmask], leaving the subject line blank.