Clinical score and rapid antigen detection test to guide antibiotic use for sore throats: randomised controlled trial of PRISM (primary care streptococcal management)BMJ 2013; 347 doi: https://doi.org/10.1136/bmj.f5806 (Published 10 October 2013) Cite this as: BMJ 2013;347:f5806
- Paul Little, general practitioner and professor of primary care research1,
- F D Richard Hobbs, professor23,
- Michael Moore, general practitioner and reader in primary care1,
- David Mant, emeritus professor2,
- Ian Williamson, general practitioner and senior lecturer in primary care1,
- Cliodna McNulty, consultant microbiologist4,
- Ying Edith Cheng, study statistician1,
- Geraldine Leydon, social scientist, principal research fellow1,
- Richard McManus, general practitioner and professor of primary care23,
- Joanne Kelly, senior trial manager1,
- Jane Barnett, senior trial manager1,
- Paul Glasziou, professor of evidence based medicine5,
- Mark Mullee, lead study statistician, director research design service1
- on behalf of the PRISM investigators
- 1University of Southampton Medical School, Aldermoore Health Centre, Southampton SO16 5ST, UK
- 2Department of Primary Care Health Services, University of Oxford, Oxford, UK
- 3University of Birmingham, Birmingham, UK
- 4Health Protection Agency-Primary Care Unit, Microbiology Department, Gloucestershire Royal Hospital, Gloucester GL1 3NN, UK
- 5Faculty of Health Science and Medicine, Bond University, Gold Coast, QLD 4229, Australia
- Correspondence to: P Little
- Accepted 30 August 2013
Objective To determine the effect of clinical scores that predict streptococcal infection or rapid streptococcal antigen detection tests compared with delayed antibiotic prescribing.
Design Open adaptive pragmatic parallel group randomised controlled trial.
Setting Primary care in United Kingdom.
Patients Patients aged ≥3 with acute sore throat.
Intervention An internet programme randomised patients to targeted antibiotic use according to: delayed antibiotics (the comparator group for analyses), clinical score, or antigen test used according to clinical score. During the trial a preliminary streptococcal score (score 1, n=1129) was replaced by a more consistent score (score 2, n=631; features: fever during previous 24 hours; purulence; attends rapidly (within three days after onset of symptoms); inflamed tonsils; no cough/coryza (acronym FeverPAIN).
Outcomes Symptom severity reported by patients on a 7 point Likert scale (mean severity of sore throat/difficulty swallowing for days two to four after the consultation (primary outcome)), duration of symptoms, use of antibiotics.
Results For score 1 there were no significant differences between groups. For score 2, symptom severity was documented in 80% (168/207 (81%) in delayed antibiotics group; 168/211 (80%) in clinical score group; 166/213 (78%) in antigen test group). Reported severity of symptoms was lower in the clinical score group (−0.33, 95% confidence interval −0.64 to −0.02; P=0.04), equivalent to one in three rating sore throat a slight versus moderate problem, with a similar reduction for the antigen test group (−0.30, −0.61 to −0.00; P=0.05). Symptoms rated moderately bad or worse resolved significantly faster in the clinical score group (hazard ratio 1.30, 95% confidence interval 1.03 to 1.63) but not the antigen test group (1.11, 0.88 to 1.40). In the delayed antibiotics group, 75/164 (46%) used antibiotics. Use of antibiotics in the clinical score group (60/161) was 29% lower (adjusted risk ratio 0.71, 95% confidence interval 0.50 to 0.95; P=0.02) and in the antigen test group (58/164) was 27% lower (0.73, 0.52 to 0.98; P=0.03). There were no significant differences in complications or reconsultations.
Conclusion Targeted use of antibiotics for acute sore throat with a clinical score improves reported symptoms and reduces antibiotic use. Antigen tests used according to a clinical score provide similar benefits but with no clear advantages over a clinical score alone.
Trial registration ISRCTN32027234
University of Southampton: Paul Little, Ian Williamson, Mike Moore, Mark Mullee, Man Ying Edith Cheng, James Raftery, David Turner, Jo Kelly, Jane Barnett, Karen Middleton, Lisa McDermott, Geraldine Leydon, Beth Stuart; University of Oxford: Richard Hobbs, Richard McManus, David Mant, Paul Glasziou, Sue Smith, Diane Coulson University of Birmingham: Razia Meer-Baloch; Health Protection Agency: Cliodna McNulty, Peter Hawtin.
We are grateful to all the patients and healthcare professionals who have contributed their time and effort and helpful insights to make PRISM possible.
Contributors: Razia Meer-Baloch (senior trial manager), day to day coordination of the Birmingham study centre, and commented on drafts of the paper. YEC developed the protocol, contributed to quantitative analysis, and drafting of the paper. PG developed the protocol for funding, contributed to management of the study, commented on the paper. FDRH developed the protocol for funding, contributed to management of all studies, supervised the Birmingham study centre, and contributed to the drafting of the paper. JK and JB developed the protocol, provided day to day overall management of the study, coordinated recruitment in the lead study centre and coordination of other centres, and commented on drafts of the paper. GL developed the protocol for funding, contributed to management, and commented on drafts of the paper. PL had the original idea for the protocol, led protocol development and the funding application, supervised the running of the lead study centre and coordination of centres, contributed to the analysis, led the drafting of the paper, and is guarantor. RMcM developed the protocol for funding, contributed to management of all studies, supervised the Birmingham Network and contributed to the drafting of the paper. DM (now emeritus professor of general practice) developed the protocol for funding, supervised the running of clinical studies in the Oxford centre and contributed to the analysis and the drafting of the paper. Lisa McDermott (social scientist; research assistant, University of Southampton), developed the protocol, and commented on drafts of the paper. CMcN and Gemma Lasseter developed the protocol and contributed to the management and write up of the study. Peter Hawtin (consultant microbiologist for the HPA) developed the protocol for funding, contributed to the design and running of the in vitro and diagnostic phases of the study. Karen Middleton (data manager, University of Southampton). Provided administrative support, developed data management protocols, coordinated data entry, and commented on drafts of the paper. M Mant developed the protocol for funding, contributed to the management of the study, contributed to the analysis and to the drafting of the paper. M Mullee, developed the protocol for funding, contributed to study management, supervised data management, led the quantitative analysis and contributed to the drafting of the paper. IW developed the protocol for funding, contributed to the management of the study, and drafted of the paper. Sue Smith, Mary Selwood, and Diane Coulson (trial managers, University of Oxford) provided day to day coordination of the Oxford study centre and commented on drafts of the paper. James Raftery, Rafael Pinedo-Villaneuva, and David Turner (Health Economics, University of Southampton) developed the protocol and led protocol development for the health economic analysis.
Funding: This project was funded by the National Institute for Health Research Heath Technology Assessment (HTA) Programme (project number 05/10/01) and will be published in full in the Health Technology Assessment journal. Further information is available at www.nets.nihr.ac.uk/projects/hta/051001. This report presents independent research commissioned by the National Institute for Health Research (NIHR). The views and opinions expressed by authors in this publication are those of the authors and do not necessarily reflect those of the NHS, the NIHR, NETSCC, the HTA programme or the Department of Health.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: The study was approved by a multicentre research ethics committee (number 06/MRE06/17), and all participants gave written informed consent.
Declaration of transparency: PL affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
Data sharing: We are happy to share data and collaborate with other investigators as appropriate (for example, in larger merged individual patient data studies).
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