Objective: To evaluate the utility of a simple scoring system as a predictor of obtaining a positive throat culture for group A streptococci (GAS).
Design: Prospective descriptive study. Scores were assigned prior to the availability of the results of throat cultures.
Setting: Emergency department and walk-in clinic of the Children's Hospital of Pittsburgh.
Patients: Patients were 365 children between the ages of two and 16 years with acute onset of sore throat and a history of or documentation of fever within the preceding 24 hours.
Interventions: A streptococcal score was assigned on the basis of a 6-point schema in which the features were 1) age; 2) season; 3) temperature of at least 38.3 degrees C; 4) adenopathy; 5) pharyngeal erythema, edema, or exudate; and 6) no symptoms of a viral upper respiratory infection (conjunctivitis, rhinorrhea, or cough). A throat culture was performed for the isolation of GAS.
Main outcome measure: Positive predictive value of the streptococcal score in identifying children with a positive throat culture for GAS.
Results: A score of 5 or 6 predicted a positive culture for GAS in 59 and 75% of children, respectively. In patients with evidence of acute pharyngitis, the combination of age between five and 15 years, fever and absence of upper respiratory symptoms predicted a positive culture for GAS in 72% of patients.
Conclusions: The score can be used to predict the likelihood that a throat culture will be positive for GAS.