Assessing and reducing risk of Crohn's disease in smokers
Current hypothesis as of 28/04/2008:
The trial objective is to describe the impact upon motivation to stop smoking using genotype to assess risk of developing Crohn's disease (CD).
The primary hypothesis is that participants are more likely to make smoking cessation attempt following the communication of their risk of developing CD that incorporates genotype analysis in addition to family history and smoking status, compared with a communication of risk of CD that does not incorporate genotype analysis.
The trial objective is to describe the impact upon motivation to stop smoking using genotype to assess risk of developing Crohn's disease.
The primary hypothesis: a higher proportion of participants will engage in one or more quit-related behaviours over the six months since the intervention.
Ethics approval receive from the Hertfordshire Research Ethics Committee on the 26th June 2006 (ref: 06/Q0201/19). Most recent Substantial Amendment (5.0): 9th October 2007.
Parallel group randomised controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
The trial objective is to describe the impact upon motivation to stop smoking of using genotype to assess risk of developing Crohn's disease. We will compare the impact of risk assessment based on family history and DNA testing versus assessment based on family history alone.
Primary outcome measure
Current primary outcome as of 28/04/2008:
Stopping smoking for 24 hours or longer in the six months following provision of risk information.
Previous primary outcome:
The proportion of participants in each group engaging in 1 or more quit-related behaviours, measured 6 months after participants are presented with their personalised risk information.
Secondary outcome measures
The proportion of participants in each group who make smoking quit attempts of 6 or more days duration. This will be validated using questionnaires and biochemical indices.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. First degree relatives of patients with Crohn's disease
2. Aged over 18 years
3. Living in the British Isles
4. Without a diagnosis of Crohn's disease or ulcerative colitis
5. Male or female
6. Smoke 5 or more cigarettes daily
7. Able to give informed consent to participate
8. Able to complete, either alone or with assistance, the study questionnaires
Target number of participants
Participant exclusion criteria
Those not meeting the inclusion criteria
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Health Psychology Section
Medical Research Council - Health Services and Public Health Research Board (HSPHRB; ref G0500274) (UK)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Whitwell SC, Mathew CG, Lewis CM, Forbes A, Watts S, Sanderson J, Hollands GJ, Prevost AT, Armstrong D, Kinmonth AL, Sutton S, Marteau TM, Trial Protocol: Communicating DNA-based risk assessments for Crohn's disease: a randomised controlled trial assessing impact upon stopping smoking., BMC Public Health, 2011, 11, 44, doi: 10.1186/1471-2458-11-44.
Hollands GJ, Whitwell SC, Parker RA, Prescott NJ, Forbes A, Sanderson J, Mathew CG, Lewis CM, Watts S, Sutton S, Armstrong D, Kinmonth AL, Prevost AT, Marteau TM, Effect of communicating DNA based risk assessments for Crohn's disease on smoking cessation: randomised controlled trial., BMJ, 2012, 345, e4708.