Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims:
Colorectal (bowel) cancer is the second leading cause of cancer death in the UK, and costs the National Health Service (NHS) more than £300 million a year in treatment costs. Patient survival could be increased and, costs very much reduced, if patients with bowel cancer received their diagnosis earlier, allowing treatment to begin earlier. The NHS Bowel Cancer Screening Programme (NHSBCSP) was introduced in England in 2006, and aims to screen men and women aged between 60 to 74 years of age for bowel cancer every two years using the faecal occult blood test (FOBt). Initial studies have shown that bowel screening is effective, but the number of patients who participate in screening have been quite low, with only around half of all the people who are invited to participate returning their FOBt kit.
The success of the NHSBCSP relies on a high number of patients participating, and the development of new ways to improve the number participating after they are invited to participate.
The main aim of the study is to assess how effective a GP reminder and additional FOBt kit are on increasing the number who participate in bowel cancer screening, when they have not participated following a previous invitation.

Who can participate?
All adults eligible for bowel screening (aged between 60 to 74 years old). These were patients at a participating general practice in the West Midlands, where the screening rate is less than 50%. These patients had been invited to participate in bowel screening but had not returned their FOBt within 13 weeks of initial invitation by the Midlands and North West Bowel Cancer Screening Hub.

What does the study involve?
We will randomly allocate the participants to one of two groups:
1. GP reminder to participate in bowel screening and additional FOBt kit, OR
2. No additional contact
We compared how may people participated in bowel screening after 13 weeks. This was measured by the number of FOBt kits that were returned to the bowel screening hub by patients in each group. This allowed us to assess if the GP reminder to participate in bowel screening and additional FOBt kit was successful in increasing the participation in bowel screening. A small interview was carried out with some patients who received the GP reminder who returned a FOBt kit.

What are the possible benefits and risks of participating?
There were no direct benefits to the patients who participated, but their participation will allow us to better understand why a person decides to take part in bowel screening, and what may put some people off participating. The findings will be used to help to identify ways to improve the NHS Bowel Cancer Screening Programme, so that future patients can benefit from a more effective screening service. There are no known risks associated with participating in this study.

Where is the study run from?
From the Department of Primary Care Clinical Sciences, at the University of Birmingham, in collaboration with the Department of Primary Healthcare at University of Oxford, and the Midlands and North West Bowel Cancer Screening Hub.

When is the study starting and how long is it expected to run for?
The study began in October 2011 and recruitment continued for approximately six months. The study ended in September 2012.

Who is funding the study?
National Institute for Health Research (NIHR) - School for Primary Care Research

Who is the main contact?
Mrs Sue Clifford

Trial website

Contact information



Primary contact

Mrs Sue Clifford


Contact details

Department of Primary Care & General Practice
Primary Care Clinical Sciences Building
B15 2TT
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Evaluating the effectiveness of GP endorsement in increasing participation in the NHS Bowel Cancer Screening Programme: A feasibility trial


Study hypothesis

This feasibility study will comprise a two-armed randomised controlled trial to evaluate the effectiveness of a GP endorsed reminder in improving patient participation in the NHS Bowel Cancer Screening Programme (NHS BC SP), and a qualitative research study to establish the perceived importance of different components of this complex intervention.

Ethics approval

First MREC, 12 July 2011, ref: 11/WM/0086

Study design

Randomised interventional process of care

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Bowel Cancer


The study population will be adults aged 60 to 74 who have been invited to participate in bowel screening but who have not returned their Faecal Occult Blood Test (FOBt) kit within the 13 week ‘screening episode’ recorded by the Midlands and North West Bowel Cancer Screening Hub. The Hub will identify general practices with a patient uptake of bowel screening less than 50%. Depending on the number of non-responders at each practice, up to 20 practices will be recruited, and approximately 4,000 people randomised in equal numbers to either the intervention (GP letter and duplicate FOBt kit) or control (no additional contact) arms of the trial.

Intervention type



Not Applicable

Drug names

Primary outcome measure

The difference in the uptake rate of FOBt screening for bowel cancer (i.e. completion and return of FOBt kit) between the intervention and control groups at 13 weeks after the GP endorsed reminder and duplicate FOBt kit are sent.

Secondary outcome measures

1. Subgroup analyses of uptake by gender, age and deprivation
2. The development and validation of methods for collecting data on intervention costs
3. Qualitative work (30-40 semi-structured interviews) will be undertaken with individuals in the intervention arm who return a FOBt kit. This will investigate the relative importance of the duplicate FOBt kit, reminder to participate, and GP endorsement of that reminder in contributing to individuals’ decisions to participate in screening. If the feasibility work demonstrates a significant increase in uptake of FOBt screening in individuals receiving the intervention, a future definitive trial can be designed and appropriately powered.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Adults aged 60 to 74
2. Non-responders to previous invitation to participate in NHS Bowel Cancer Screening Programme
3. Target Gender: Male & Female

Participant type


Age group




Target number of participants

Planned Sample Size: 4380; UK Sample Size: 4380; Description: Patients will be randomised to the intervention or control arms of the study in the ratio of 1:1

Participant exclusion criteria

1. Recently undergone an investigation and/or are currently under surveillance.
2. Moved outside age range for screening.
3. Have contacted Hub requesting no further contact.

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Department of Primary Care & General Practice
B15 2TT
United Kingdom

Sponsor information


University of Birmingham (UK)

Sponsor details

B15 2TT
United Kingdom
+44 (0)121 414 3344

Sponsor type




Funder type


Funder name

NIHR School for Primary Care Research

Alternative name(s)

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)

END OF STUDY SUMMARY: Evaluating the effectiveness of GP Endorsement in increasing participation in the NHS Bowel Cancer Screening Programme: a feasibility trial

This study was a two armed randomised controlled trial to evaluate the effectiveness of a GP endorsed reminder in improving patient participation in the NHS Bowel Cancer Screening Programme. The study population was patients aged between 60-74 years who were invited to participate in bowel screening but who did not return their faecal occult blood testing (FOBt) screening kit within the 13-week screening episode ‘window’ defined by the Midlands and North West Bowel Screening Hub in Rugby.
Those eligible for inclusion in the trial were registered at one of 22 general practices recruited to the study from within the West Midlands, all of which had a bowel screening uptake rate of lower than 50% in the 12 months prior to the trial.
Eligible patients were randomised in equal proportions (1:1 randomisation ratio), stratified by GP practice to intervention or control arms of the study. The intervention was a personalised letter from a patient’s GP recommending (‘endorsing’) bowel screening, and an additional FOBt kit. Patients in the control arm received no additional contact or information.
The primary outcome was the difference in screening uptake rate between intervention and control groups at 13 weeks after the intervention (i.e. the proportion of individuals who returned the FOBt kit in each group after 13 weeks). Secondary outcomes included a sub-group analysis of screening uptake according to gender, age, level of socioeconomic deprivation, previous screening history and time to response.

Sample size
The pre-trial sample size calculation stated that 4,380 individuals were needed in total (half in the intervention arm, half in the control arm), in order to estimate the uptake of screening with a precision of at least 3.25% in each group. This assumed an uptake rate of 3.2% in the control group, with 934 in each group sufficient to demonstrate a doubling of the uptake rate to 6.4% in the intervention group at 90% power and 5% significance. This would equate to around 140 screening kits being returned in the intervention group and around 70 in the control group.

Research findings
The findings showed that GP endorsement of bowel cancer screening can increase the uptake of screening in previous non-responders to screening invitations. 4,737 patients were included in the study: 2,371 in the intervention arm, and 2,366 in the control arm. A total of 119 screening kits were returned in the intervention group (5.0%), compared to just 15 returned in the control group (0.6%). This gives an odds ratio of 8 i.e. patients in the intervention arm, who received a GP endorsement of bowel screening and an additional FOBt kit, were 8 times more likely than controls to participate in bowel cancer screening.

Sub-group analysis
Males were significantly less likely to return a kit within the trial than women (p=0.007), as were older individuals and those in the most socioeconomically deprived deprivation quartile. There were also significant differences in the response to the trial invitation if participants had taken part in the previous screening episode: those who had sent a kit back prior to the trial, even if this was in response to an invitation several years before, were more likely to return to trial kit. Duration of time between a previous screening invitation and the trial invitation was significantly different, as might be expected: in situations where individuals had a shorter time between the trial and their previous screening invitation, they were more likely to return the kit within the trial.

If this intervention was rolled out on a national basis, we would expect to find (approximately) 350 additional cases of bowel cancer in a 12-month period due to the larger number of screening non-responders participating in screening as a result of the intervention. Although the findings will not in themselves improve patient care, as by definition, asymptomatic individuals who are invited to participate in cancer screening are not ‘patients’, but as the intervention has been shown to improve the uptake of bowel cancer screening in patients who have formerly been reluctant to do so, it is a promising intervention. As this was a feasibility trial, primarily designed to establish the feasibility of trial processes and administering the intervention, the study should not be considered to show a definitive answer – the overall number of test kits returned even in the intervention arm was still fairly low, at 5%, and it must be questioned whether or not this approach would be cost-effective if carried out routinely and on a larger scale. There were also two elements to the intervention: both the additional FOBt kit AND the GP endorsement letter. We were unable in this study to disaggregate which of these two elements had the most impact on determining return of the bowel screening kit to the screening hub, and future work should include a factorial trial and full cost-effectiveness analysis to determine the optimal and most cost-efficient way to enhance bowel screening uptake amongst non-responders to a screening invitation.

Publication list

1. 2012 study protocol in

Publication citations

  1. Study protocol

    Damery S, Smith S, Clements A, Holder R, Nichols L, Draper H, Clifford S, Parker L, Hobbs R, Wilson S, Evaluating the effectiveness of GP endorsement on increasing participation in the NHS Bowel Cancer Screening Programme in England: study protocol for a randomized controlled trial., Trials, 2012, 13, 18, doi: 10.1186/1745-6215-13-18.

Additional files

Editorial Notes

05/09/2018: Results summary added. 30/08/2018: Dr Sarah Damery confirmed that the trial results have not been published. 29/08/2018: No publications found, verifying study status with principal investigator.