Diagnostic accuracy of Fever-PAIN and Centor criteria for bacterial throat infection in adults with sore throat: a secondary analysis of a randomised controlled trial.

Anna Seeley,Thomas Fanshawe,Michael Moore,Alastair Hay,Merryn Voysey,Gail Hayward

doi:10.3399/bjgpo.2021.0122

Abstract

BackgroundSore throat is a common and self-limiting condition. There remains ambiguity in stratifying patients to immediate, delayed, or no antibiotic prescriptions. The National Institute for Health and Care Excellence (NICE) recommends two clinical prediction rules (CPRs), FeverPAIN and Centor, to guide decision making.AimTo describe the diagnostic accuracy of CPRs in identifying streptococcal throat infections.Design & settingAdults presenting to UK primary care with sore throat, who did not require immediate antibiotics.MethodAs part of the Treatment Options without Antibiotics for Sore Throat (TOAST) trial, 565 participants, aged ≥18 years, were recruited on day of presentation to general practice. Physicians could opt to give delayed prescriptions. CPR scores were not part of the trial protocol but were calculated post hoc from baseline assessments. Diagnostic accuracy was calculated by comparing scores with throat swab cultures.ResultsIt was found that 81/502 (16.1%) patients had group A, C, or G streptococcus cultured on throat swab. Overall diagnostic accuracy of both CPRs was poor: area under receiver operating characteristics (ROC) curve 0.62 for Centor; and 0.59 for FeverPAIN. Post-test probability of a positive or negative test was 27.3% (95% confidence interval [CI] = 6.0% to 61.0%) and 84.1% (95% CI = 80.6% to 87.2%) for FeverPAIN ≥4; versus 25.7% (95% CI = 16.2% to 37.2%) and 85.5% (95% CI = 81.8% to 88.7%) for Centor ≥3. Higher CPR scores were associated with increased delayed antibiotic prescriptions (χ2 = 8.42, P = 0.004 for FeverPAIN ≥4; χ2 = 32.0, P<0.001 for Centor ≥3).ConclusionIn those who do not require immediate antibiotics in primary care, neither CPR provides a reliable way of diagnosing streptococcal throat infection. However, clinicians were more likely to give delayed prescriptions to those with higher scores.

Highlights

Sore throats are a common presentation in UK primary care, accounting for around 3.5 million appointments per year.[1]
Post-t est probability of a positive or negative test was 27.3% (95% confidence interval [CI] = 6.0% to 61.0%) and 84.1% for FeverPAIN ≥4; versus 25.7% and 85.5% for Centor ≥3
Higher clinical prediction rules (CPRs) scores were associated with increased delayed antibiotic prescriptions (χ2 = 8.42, P = 0.004 for FeverPAIN ≥4; χ2 = 32.0, P

Summary

Introduction

Sore throats are a common presentation in UK primary care, accounting for around 3.5 million appointments per year.[1]. NICE guidelines on sore throat infection recommend use of two CPRs to inform antibiotic prescribing strategies.[4] The Centor score was developed in the 1980s in adults presenting to emergency departments, and allocates one point to presence of cervical lymph nodes, fever, tonsillar exudates, or absence of cough.[5] NICE recommends immediate or delayed antibiotics for a score of ≥3, associated with a 32–56% chance of streptococcal infection. FeverPAIN was derived from UK primary care populations and is a 5-p oint scale with a point for fever, absence of cough, and purulent tonsils, as per Centor, and for severe tonsillar exudate and duration of symptoms of less than 3 days.[8] It incorporates three clinical decisions: no antibiotics (0–1); a delayed prescription (2-3 );[2,3] and immediate antibiotics (4-5 ),[4,5] with scores in the latter category associated with a 60–65% chance of group A, C, or G streptococcal infection.

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