Predicting streptococcal pharyngitis in adults in primary care: a systematic review of the diagnostic accuracy of symptoms and signs and validation of the Centor score

Abstract

BackgroundStratifying patients with a sore throat into the probability of having an underlying bacterial or viral cause may be helpful in targeting antibiotic treatment. We sought to assess the diagnostic accuracy of signs and symptoms and validate a clinical prediction rule (CPR), the Centor score, for predicting group A β-haemolytic streptococcal (GABHS) pharyngitis in adults (> 14 years of age) presenting with sore throat symptoms.MethodsA systematic literature search was performed up to July 2010. Studies that assessed the diagnostic accuracy of signs and symptoms and/or validated the Centor score were included. For the analysis of the diagnostic accuracy of signs and symptoms and the Centor score, studies were combined using a bivariate random effects model, while for the calibration analysis of the Centor score, a random effects model was used.ResultsA total of 21 studies incorporating 4,839 patients were included in the meta-analysis on diagnostic accuracy of signs and symptoms. The results were heterogeneous and suggest that individual signs and symptoms generate only small shifts in post-test probability (range positive likelihood ratio (+LR) 1.45-2.33, -LR 0.54-0.72). As a decision rule for considering antibiotic prescribing (score ≥ 3), the Centor score has reasonable specificity (0.82, 95% CI 0.72 to 0.88) and a post-test probability of 12% to 40% based on a prior prevalence of 5% to 20%. Pooled calibration shows no significant difference between the numbers of patients predicted and observed to have GABHS pharyngitis across strata of Centor score (0-1 risk ratio (RR) 0.72, 95% CI 0.49 to 1.06; 2-3 RR 0.93, 95% CI 0.73 to 1.17; 4 RR 1.14, 95% CI 0.95 to 1.37).ConclusionsIndividual signs and symptoms are not powerful enough to discriminate GABHS pharyngitis from other types of sore throat. The Centor score is a well calibrated CPR for estimating the probability of GABHS pharyngitis. The Centor score can enhance appropriate prescribing of antibiotics, but should be used with caution in low prevalence settings of GABHS pharyngitis such as primary care.

A feasibility service evaluation of screening and treatment of group A streptococcal pharyngitis in community pharmacies

“…Trained pharmacy staff assessed the patient's presenting condition using the Centor scoring system. 15 This is a four-point validated method that helps to identify the likelihood of bacterial infection in adults with a sore throat. Patients who had a history of fever and/or absence of cough were referred to the pharmacist to complete the second part of the Centor scoring system, i.e.…”

Influence of the duration of penicillin prescriptions on outcomes for acute sore throat in adults: the DESCARTE prospective cohort study in UK general practice

“…The Centor score derived in hospital outpatients is used to predict the probability of Streptococcal infection, has been shown to be related to response to antibiotics and is widely used internationally. 33,34 The FeverPAIN score may also be used to predict the probability of streptococcal infection (A,C&G) in community samples and has been shown to be highly predictive of time to symptom resolution and symptom severity. 25 The FeverPAIN score comprises fever in the past 24 hours, purulence, rapid attendance (within three days), inflamed tonsils and no cough or cold symptoms.…”

What is the test's accuracy in my practice population? Tailored meta-analysis provides a plausible estimate

“…The target disorder was GABHS, and a throat swab was considered to be a suitable reference standard (see Appendix D at www.jclinepi.com for details). In addition, the references from a previous meta-analysis were located [26].…”