Condition category
Infections and Infestations
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Antibiotics are vitally important medicines. They are used to treat infections caused by bacteria, some of which would otherwise kill the person affected. In recent years, however, antibiotic resistance, a situation where an antibiotic no longer works against one or more bacteria, has become a major problem. It has been caused by a number of factors, including general practitioners (GPs) prescribing them for minor illnesses that do not need them or for conditions that antibiotics can’t cure (such as the common cold). Here, we are going to test whether an electronically delivered, multi-component intervention can reduce the number of unnecessary antibiotic prescriptions given to patients that go to their GP about a respiratory tract infection (RTI – an infection of the sinuses, throat, airways or lungs).

Who can participate?
General practices that contribute up-to-standard data to the Clinical Practice Research Datalink (CPRD), the NHS observational data and interventional research service.

What does the study involve?
Participating CPRD general practices are randomly allocated into one of two groups. Those in the control group continue with their usual clinical care. Those in the interventional group receive an intervention made up of a number of parts. These include feedback on their rate of antibiotic prescribing compared to other GP practices, educational and decision support tools to support the none prescribing or delayed prescribing of antibiotics, and three minute webinars that explain and promote the use of the materials they are given. The study is run for 12 months, after which the antibiotic prescribing rates between the intervention and control groups are made, along with other outcome measures such as RTI consultation rate, health care costs, number of cases of pneumonia and lower respiratory tract infections and hospital admissions.

What are the possible benefits and risks of participating?
This research looks at inappropriate and unnecessary prescribing of antibiotics to patients with respiratory tract infections (RTIs) in general practice. All management decisions for individual patients remain at the discretion of individual general practitioners. Therefore, we do not anticipate any potential serious adverse events that could be directly caused by the intervention. However, we will ask general practitioners at participating general practices to tell us of any possible adverse events.

Where is the study run from?
King’s College London (UK)

When is the study starting and how long is it expected to run for?
January 2015 to December 2018

Who is funding the study?
National Institute for Health Research (UK)

Who is the main contact?
Professor Martin Gulliford

Trial website

Contact information



Primary contact

Prof Martin Gulliford


Contact details

King's College London
Department of Primary Care and Public Health Sciences
Capital House
52 Weston Street
United Kingdom
+44 (0)2078486631

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Electronically delivered, multi-component intervention to reduce unnecessary antibiotic prescribing in primary care. Cluster randomised trial using electronic health records (eCRT2)



Study hypothesis

To test the effectiveness, in a cluster randomised controlled trial, of electronically delivered, multi component interventions to reduce unnecessary antibiotic prescribing when patients consult for respiratory tract infections (RTI) in primary care.

Ethics approval

NRES London Dulwich, 08/10/2014, ref. 14/LO/1730.

Study design

Cluster randomised trial with general practices as the unit of allocation

Primary study design


Secondary study design

Cluster randomised trial

Trial setting

GP practices

Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Antibiotic prescribing/respiratory tract infections


There will be two trial arms.
1. The control trial arm practices will continue with usual clinical care.
2. Practices in the Intervention trial arm will receive complex multi-component interventions, delivered remotely, as follows:
2.1. Feedback of each practice’s antibiotic prescribing results in relation to peers, through monthly updated antibiotic prescribing reports estimated from CPRD data
2.2. Delivery of educational and decision support tools to support policies of no-antibiotic prescribing or delayed prescribing
2.3. ‘Three minute webinars’ to explain and promote effective utilisation of the intervention materials. The intervention will continue for 12 months.

Intervention type



Not Applicable

Drug names

Primary outcome measure

Number of antibiotic prescriptions for RTI per 1,000 registered patient years at 12 months follow-up

Secondary outcome measures

1. Number of consultations for RTI with antibiotic prescribed / Total RTI consultations (%) at 12 months follow-up
2. Consultations and prescriptions as defined above during 14 days after the index consultation at 12 months follow-up
3. Number of consultations for RTI per 1,000 registered patient years 12 months follow-up
4. All antibiotic prescriptions per 1,000 registered patient years at 12 months follow-up
5. Number of hospital admission (by category) per 1,000 registered patient years at 12 months follow-up
6. Estimated costs of all health care utilisation per 1,000 registered patient years at 12 months follow-up
7. Broad categories of RTI subgroups including colds, sore throat, cough and bronchitis, otitis media and rhino-sinusitis (NICE, 2008) at 12 months follow-up
8. Number of adverse events ((peritonsillar abscess, mastoiditis, skin infections and bacterial infections) (by category) per 1,000 registered patient years over at 12-months follow-up

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

General practices will be included in the trial if:
1. They presently contribute up-to-standard data to CPRD
2. Consent to participation in the trial
3. Are located in areas that have given research governance approval for the study

Data for non-trial CPRD practices will be eligible for observational data analysis to gauge the representativeness of practices and patients participating in the trial.
Data for individual participants will be included if they are currently registered with CPRD general practices

Participant type


Age group




Target number of participants


Participant exclusion criteria

No other exclusion criteria

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

King's College London
United Kingdom

Sponsor information


National Institute for Health Research (UK)

Sponsor details

Trials and Studies Coordinating Centre
University of Southampton
Alpha House
Enterprise Road
SO16 7NS
United Kingdom

Sponsor type




Funder type


Funder name

Health Technology Assessment Programme (Ref: 13/88/10)

Alternative name(s)

NIHR Health Technology Assessment Programme, HTA

Funding Body Type

government organisation

Funding Body Subtype

National government


United Kingdom

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)


Publication list

1. 2016 protocol in:
2. 2019 results in:

Publication citations

Additional files

Editorial Notes

25/03/2019: Publication reference added. 08/01/2019: The following changes have been made: 1. The recruitment end date has been updated from 31/12/2018 to 30/09/2018. 2. The intention to publish date has been set to 31/12/2019. 08/08/2016: Publication reference added.