Use of the TwiCs design is growing.

Studies using the TwiCs design have obtained ethics board approval in: Australia, Brazil, Canada, China, Congo & Uganda, Denmark, Finland, France, Germany, India, Iran, Ireland Italy, Norway, Mexico, Netherlands, Spain, USA.  

Below are examples of some of the studies. We have provided links to protocols, publications, and study contacts. Our list is not definitive. 

If there is anything that should be included please do contact us at:

Use of the TwiCs design

Studies using

the TwiCs design

Studies using

the TwiCs design



This study aims to determine if a telephone based lifestyle behavioural intervention is effective in reducing pain intensity in overweight or obese patients with low back pain, compared to usual care.

The study protocol was published here.  

The protocol for a causal mediation analysis of two trials in the project is here



This study aims to provide a better understanding of the relationship between cognitive complaints, depression and HIV, and to facilitate trials of interventions to improve brain health in HIV

The protocol for the study can be found here.

The trials nested within this cohort are registered as NCT02571504 and NCT02571595

For more information contact: Nancy E Mayo


FORBOW (Families Overcoming Risks and Building Opportunities);  This project  is recruiting the offspring of parents with severe mental illness including schizophrenia, bipolar disorder and severe depression. It aims to test multiple interventions to reduce the risk of developing mood or psychotic disorders. The study began recruiting young people at risk in Canada in 2013. The link to the published protocol can be found here. 

For more information contact Rudolf Uher at,


THE CEDAR PROJECT:  is an ongoing longitudinal cohort study addressing HIV and Hepatitis C vulnerability among young indigenous people who use drugs in Vancouver and Prince George, Brisith Columbia, Canada.The first trial use the cmRCT/ TwiCs approach is testing the impact of mHealth for HIV Prevention Among Young Indigenous People Who Use Illicit Drugs. The protocol for the trial (described as a multi-site Zelen pre-randomised trial) is published by BMC Central and the Clinical Trials registration can be found here.

SPIN Scleroderma Patient-Centred Intervention Network: This CIHR funded study is recruiting an international cohort of people with the rare disease - scleroderma (Canada, France, USA, UK, France, Mexico) .  Over 1400 people have enrolled to date (August 2016). Four trials of interventions to help people manage this condition are ongoing. The protocol can be found here.

Funding for two further trials was obtained in July 2016.

For more information contact Brett Thombs,


The Alberta's Caring for Diabetes (ABCD) Cohort Study is being used to test interventions for patients with diabetes and depression. The protocol for the TeamCare-PCN trial is here.


FIDELITY: The Finnish Degenerative Meniscal Lesion Study (FIDELITY) This multi centre trial aims to determine whether arthroscopic partial meniscectomy of patients with degenerative meniscus injury is improved by a number of different types of surgery.

For further information contact:


 A group based in the Netherlands led by Helena Verkooijen have established three cohorts using the TwiCs approach. See this link.



This ongoing study is based in the University Medical Center, Utrecht, The Netherlands. The study started life as the ProspectIve data CollectioN Initiative on Colorectal cancer (PICNIC) study - a prospective observational cohort study.  This study is now national and has changed its name.

The links to the study protocol can be found here or here

Other publications: 

For more information contact:

UMBRELLA: The Utrecht cohort for Multiple BREast cancer intervention studies and Long-term evaLuAtion'

This study is based in the Department of Radiotherapy, University Medical Center in Utrecht, The Netherlands. The link to the study protocol can be found here

Other publications

For more information contact:,

PRESENT – Bone metastases

This ongoing study is based at the University Medical Centre in Untrech. 

The protocol for the first trial based in the cohort comparing conventional radiotherapy with stereotactic body radiotherapy in patients with spinal metastases can be found here

For more information contact:




ASSESS-meso:  This is a prospective, observational cohort study aiming to collect information on 700 patients diagnosed with mesothelioma over the next 10 years.  This will provide a much-needed picture of the natural history of the disease, as well as symptom course and outcomes.  The study is currently recruiting in Bristol and Oxford, with 8 further sites in set-up across the UK.  ASSESS-meso is funded by the Avon Mesothelioma Foundation. Within ASSESS-meso, we have designed TILT - a Trial of Intra-pleural bacteriaL immunoTherapy, using the TwiC methodology.  This is an NIHR-funded feasibility study of a novel treatment, with embedded qualitative interviews to explore participants' experiences.  We are aiming to open to recruitment in October 2017. For any information on either study, please contact

CYSTIC FIBROSIS HEALTHHUB DATA OBSERVATORY: this UK (NIHR funded) quality improvement project and Trials within Cohorts platform for Cystic Fibrosis (CF) aims to recruit 6,000 adults with CF to help research projects including trials of interventions for CF. For more information contact The protocol and PIS are available here.

YORKSHIRE HEALTH STUDY: Ongoing population based regional cohort aiming to improve long term health of the region. Recruitment initally through GP practices in South Yorkshire, then widened to the Yorkshire region. Two waves of data collection (2010-2012, and 2013-2015), further waves planned. 22 studies have recruited through the cohort including several trials (DEPSY)

For more information contact

DEPSY:  This pragmatic trial using the “cohort multiple randomised controlled trial” design tested the effectiveness of adjunctive treatment by homeopaths compared to usual care alone, over a period of 12 months in 577 patients with self-reported depression. This is the first published completed trial using the cmRCT design (link). To read about the benefits and challenges experienced in the use of this trial design see the link to this article published in the journal Trials

MENOPAUSAL HOT FLUSH STUDY: This was the first (partial) pilot of the cmRCT design. A small cohort of women with severe/ frequent menopausal hot flushes were recruited to the observational study and one RCT conducted testing the effectiveness of the offer of a course of treatment by a homeopath compared to no offer. The trial was published in Contemporary Clinical Trials..

For more information contact


CLASSIC (Comprehensive Longitudinal Assessment of Salford Integrated Care) study: This NIHR funded study is testing the implementation and effectiveness of new models of care for people with long term conditions. The cohort of 4,000 is being recruited through GP practices in  the Salford area of the UK. The study protocol can be found here.

For more information please contact

BIBBS (Born in Bradford Better Start Study):  An experimental birth cohort study designed to evaluate the impact of early life interventions. The cohort plans to recruit 5,000 babies and their mothers and mother's partners over 5 years by 2020 and test a number of interventions to improve health and social outcomes during the critical early years.

For more information contact

CARE (The Yorkshire & Humber Community Ageing Research Study): This cohort is recruiting 1,000 patients over 75 years registered with GP practices in the Yorkshire & Humber area of the UK. The researchers plan to trial interventions to improve health and wellbeing in this population. This study is funded by the NIHR CLAHRC YH.

The study is registered here and the study website is here

For more information contact: or

REFORM:  This cohort was initially formed in order to conduct a cmRCT of a multifaceted podiatry intervention for the prevention of falls in older people. The study originally recruited 2,600 people from routine podiatry clinics to the REFORM cohort. During 2016-17, this cohort is being utilised to test a second intervention to prevent falls in the elderly - details of which can be found here. 

The link to the original REFORM cohort study and trial protocol is here.

The study is led by David Torgerson at York University in the UK.

The results of this trial are now published


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