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The TARGET cohort study protocol: a prospective primary care cohort study to derive and validate a clinical prediction rule to improve the targeting of antibiotics in children with respiratory tract illnesses

Niamh M Redmond1*, Rachel Davies2, Hannah Christensen3, Peter S Blair3, Andrew M Lovering4, John P Leeming4, Peter Muir5, Barry Vipond5, Hannah Thornton1, Margaret Fletcher6, Brendan Delaney7, Paul Little8, Matthew Thompson9, Tim J Peters10, Alastair D Hay1 and on behalf of The TARGET team

Author Affiliations

1 Centre for Academic Primary Care, School of Social and Community Based Medicine, NIHR School of Primary Care Research, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol, UK

2 Research Enterprise and Development, University of Bristol, Senate House, Tyndall Avenue, Bristol, UK

3 School of Social and Community Based Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol, UK

4 Bristol Centre for Antimicrobial Research and Evaluation (BCARE), North Bristol NHS Trust. Southmead Hospital, Bristol, UK

5 Specialist Virology Centre, Public Health Laboratory Bristol, Public Health England, Myrtle Road, Bristol, UK

6 Faculty of Health and Social Care, University of the West of England Bristol, Coldharbour Lane, Bristol, UK

7 Department of Primary Care & Public Health Sciences, King’s College London, School of Medicine, 5th Floor Capital House, 42 Weston Street, London, UK

8 Department of Primary Care & Population Sciences, University of Southampton, Aldermoor Health Centre, Aldermoor Close, Southampton, UK

9 Department of Primary Care Health Sciences, Radcliffe Observatory Quarter, Woodstock Road, Oxford, UK

10 School of Clinical Sciences, University of Bristol, 69 St Michael’s Hill, Bristol, UK

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BMC Health Services Research 2013, 13:322  doi:10.1186/1472-6963-13-322

Published: 17 August 2013



Children with respiratory tract infections are the single most frequent patient group to make use of primary care health care resources. The use of antibiotics remains highly prevalent in young children, but can lead to antimicrobial resistance as well as reinforcing the idea that parents should re-consult for similar symptoms. One of the main drivers of indiscriminate antimicrobial use is the lack of evidence for, and therefore uncertainty regarding, which children are at risk of poor outcome. This paper describes the protocol for the TARGET cohort study, which aims to derive and validate a clinical prediction rule to identify children presenting to primary care with respiratory tract infections who are at risk of hospitalisation.


The TARGET cohort study is a large, multicentre prospective observational study aiming to recruit 8,300 children aged ≥3 months and <16 years presenting to primary care with a cough and respiratory tract infection symptoms from 4 study centres (Bristol, London, Oxford and Southampton). Following informed consent, symptoms, signs and demographics will be measured. In around a quarter of children from the Bristol centre, a single sweep, dual bacterial-viral throat swab will be taken and parents asked to complete a symptom diary until the child is completely well or for 28 days, whichever is sooner. A review of medical notes including clinical history, re-consultation and hospitalisations will be undertaken. Multivariable logistic regression will be used to identify the independent clinical predictors of hospitalisation as well as the prognostic significance of upper respiratory tract microbes. The clinical prediction rule will be internally validated using various methods including bootstrapping.


The clinical prediction rule for hospitalisation has the potential to help identify a small group of children for hospitalisation and a much larger group where hospitalisation is very unlikely and antibiotic prescribing would be less warranted. This study will also be the largest natural history study to date of children presenting to primary care with acute cough and respiratory tract infections, and will provide important information on symptom duration, re-consultations and the microbiology of the upper respiratory tract.

Cohort study; Children; Respiratory tract infections (RTIs); Primary care; Protocol; Throat swab