Methodological articles

 

Benefits and challenges of using the cohort multiple randomised controlled trial design for testing an intervention for depression

The first completed full trial using the cmRCT design testing an intervention for self-reported depression was associated with a number of important benefits. Further research is required to compare the acceptability and cost effectiveness of standard pragmatic RCT design with the cmRCT design.

Viksveen P, Relton C and Nicholl J Trials (2017) 18:308  doi: 10.1186/s13063-017-2059-4.

 

Cohort Multiple Randomised Controlled Trials (cmRCT) design: efficient but biased? A simulation study to evaluate the feasibility of the Cluster cmRCT design

This article reports a number of simple simulations evaluating a hypothetical cluster RCT in patients at risk of CVD. The authors conclude that based on these simulation studies the ITT effect in routine practice is likely to lie somewhere between the ITT and IV estimates from the trial – depending on refusal rates.

Pate A, Candlish J, Sperrin M and Van Staa TP on behalf of GetReal Work Package BMC Medical Research Methodology (2016) 16:109.  doi: 10.1186/s12874-016-0208-1. 

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Prospective Dutch colorectal cancer cohort: an infrastructure for long-term observational, prognostic, predictive and (randomized) intervention research

This article describes the rationale for and design of the Prospective Dutch ColoRectal Cancer cohort - a large observational cohort study, serving as a multiple trial and biobanking facility. Seven months after initiation 650 patients have been recruited and 9 embedded cohort or cmRCT designed studies are currently recruiting patients.

Burbach JP, Kurk SA, Coebergh van den Braak RR, Dik VK, May AM, Meijer GA, Punt C, Vink GR, Los M, Hoogerbrugge N, Huijgens PC,Ijzermans JN, Kuipers EJ de Noo ME, Pennings JP, van der Velden AM, Verhoef C, Siersema PD, van Oijen MG, Verkooijen HM and Koopman M  Acta Oncologica (2016) 25:1-8.

 

The cohort multiple randomized controlled trial design: a valid and efficient alternative to pragmatic trials?

This article evaluates the methodological challenges of conducing RCTS within a cohort. The authors conclude that equally valid results can be obtained from trials conducted within cohorts as from standard stand alone pragmatic RCTs.  However, the efficiency of the design compared to the standard pragmatic RCT depends on the amount and nature of non-compliance in the intervention arm.
van der Velden JM, Verkooijen HM, Young-Afat DA, Burbach JPM, van Vulpen M, Relton C, van Gils CH, May AM and Groenwold RHH International Journal of Epidemiology (2016) 1–7 doi: 10.1093/ije/dyw050.

 

Staged-informed consent in the cohort multiple randomized controlled trial design

A key feature of the cmRCT design is that informed consent is 'patient centred' i.e. the process of obtaining patient consent replicates that in real world routine health care, where patients are not told that their treatment will be decided by chance, nor are they told about treatments that they cannot then receive.  However, there is disagreement as to whether control groups should be informed that they have been randomised to not receive an new intervention being trialled/ tested for their condition. The authors have adapted the cmRCT design where in the first stage, at entry into the cohort, all potential participants are asked for consent to be randomly selected to be approached for experimental interventions or to serve as controls without further notice. This staged-informed consent procedures allows triallists to use the TwiCs approach but avoids pre-randomisation.

Young-Afat DA, Verkooijen HM, Van Gils CH, Van der Velden JM, Burbach J, Elias SG, Van Delden J, Relton C, Van Vulpen M and Van der Graaf R Epidemiology (2016).

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