Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
Not yet recruiting

Plain English Summary

Lay summary under review with external organisation

Trial website

Contact information



Primary contact

Ms Kristina Londakova


Contact details

The Behavioural Insights Team
4 Matthew Parker Street
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A behaviourally-informed intervention to address low numbers of suspected cancer (two-week wait) referrals made by GPs in the Greater Manchester area


Study hypothesis

This study aims to test whether sending GPs a series of behaviourally-informed letters increases the number of referrals to secondary care for suspected cancer by GPs in Greater Manchester.

Ethics approval

Not provided at time of registration

Study design

Stepped-wedged randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

GP practices

Trial type


Patient information sheet

No participant information sheet available




Three behaviourally informed letters to each GP practice in Greater Manchester which refers fewer patients via the 2WW referral rate than the England average. Each letter will be sent to one named GP and the practice manager at the GP surgeries that meet our criteria.

Letter 1: Anticipated feedback
This first letter will tell GP practices that they will shortly be receiving feedback on their performance. This letters aims to create anticipation and so increase the salience of the second letter. We also provide context about why we are sending the information: "Almost half of people who develop cancer are diagnosed late. In the next few weeks, I will be sending you feedback on how your practice’s two-week wait (suspected cancer) referral rate compares to other practices in your area."

Letter 2: Social norm feedback with reminder sticker
The second letter will contain the feedback on GP practices, based on the publicly available PHE age-and-sex standardised two-week wait cancer referral ratios in 2015-2016. We will divide the GP surgeries into two groups: those with very low referral rates (defined as the lowest performing 30% within Greater Manchester) and those with low referral rates (defined as those practices that perform below the England average but better than the bottom 30%). The groups will receive the following messages: Practices with very low referral rates: “The great majority (70%) of practices in Greater Manchester have a higher two-week wait cancer referral rate than yours. Two-week wait cancer referrals are critical for detecting cancer early.” Practices with low referral rates: “Many practices in Greater Manchester have a higher two -week wait cancer referral rate than yours. Two-week wait cancer referrals are critical for detecting cancer early.” As well as giving feedback about their relative performance the letter includes practical suggestions designed to help GPs make better referrals decisions and a sticker to serve as a timely prompt.

Letter 3: Reminder
The final letter serves as a reminder of the feedback and is meant to reinforce the feedback message. The groups will receive the following reminder messages:
Practices with very low referral rates: “Recently we wrote to you to tell you that your practice had a lower two-week wait cancer referral rate than the vast majority (70%) of practices in Greater Manchester.”
Practices with low referral rates: “Recently we wrote to you to tell you that your practice had a lower two-week wait cancer referral rate than many practices in Greater Manchester.”
The reminder letters again provide suggestions relating to the 2WW referral route.

The impact of the letters will be measured using a stepped-wedge design randomised at the GP practice level. This involves a sequential roll-out of the intervention to GP practices over a number of months. In this study, the intervention (the series of three letters) will be rolled out over 6 months.

Each step is one month long, this means that all three letters will be sent in the month. The letters will be sent approximately one week apart. By the end of the trial, all GP practices will have received the intervention, although the order in which GP practices receive the intervention is determined at random. The trial starts with an initial period where no GP practices receive the letters. Subsequently, each month a group of GP practices will be randomly selected to receive the letters. This process continues until all GP practices who have a referral rate below the England average have been sent the letters. Over the course of the trial period a total of 1,638 letters will be sent to 273 GP practices in Greater Manchester (three letters for the named GP and three letters for the practice manager for each GP practice).

Intervention type



Drug names

Primary outcome measures

GP referral for suspected cancer is measured using the age-and-sex-adjusted ratio at 4 weeks after the receipt of intervention.

Secondary outcome measures

No secondary outcome measures

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. GP Practices
2. Operating within Greater Manchester
3. Operating in 2017
4. Data is available in the PHE Fingertips Cancer Services data
5. For the experimental sample: the practice is referring fewer patients with suspected cancer via the 2WW than the 2015/16 England average

Participant type

Health professional

Age group




Target number of participants

273 GP practices, e.g. 273 GP leads and 273 practice managers

Participant exclusion criteria

1. Outside the Greater Manchester area
2. Within the Greater Manchester area who are performing above the England average are excluded from
the experimental group but included as additional control observations
3. In Greater Manchester for whom publicly available data is not available on the PHE Fingertips website
4. For whom data on their referral rate was unavailable from provider trusts or referral centres

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Greater Manchester Health and Social Care Partnership
3 Piccadilly Place
M1 3BN
United Kingdom

Sponsor information


Greater Manchester Health & Social Care Partnership

Sponsor details

3 Piccadilly Place
M1 3BN
United Kingdom

Sponsor type




Funder type


Funder name

Greater Manchester Health & Social Care Partnership

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in an internal report, on BIT's website and potentially, in a high-impact peer reviewed journal, in 2018.

IPD Sharing plan:
The datasets generated during and/or analysed during the current study are/will be available upon request from

Intention to publish date


Participant level data

Available on request

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes