A CLINICAL SCORE TO REDUCE UNNECESSARY ANTIBIOTIC USE IN PATIENTS WITH SORE THROAT

Objective: To validate a score based on clinical symptoms and signs fo r the identification of group A Streptococcus (GAS) infection in gener al practice patients with sore throat. Design: A single throat swab wa s used as the gold standard for diagnosing GAS infection. Clinical inf ormation was recorded by experienced family physicians on standardized encounter forms. Score criteria were identified by means of logistic regression modelling of data from patients enrolled in the first half of the study. The score was then validated among the remaining patient s. Setting: University-affiliated family medicine centre in Toronto. P atients: A total of 521 patients aged 3 to 76 years presenting with a new upper respiratory tract infection from December 1995 to February 1 997. Outcome measures: Sensitivity, specificity and likelihood ratios for identification of GAS infection with the score approach compared w ith throat culture. Proportion of patients prescribed antibiotics, thr oat culture use, and sensitivity and specificity with usual physician care and with score-based recommendations were compared. Results: A sc ore was developed ranging in value from 0 to 4. The sensitivity of the score for identifying GAS infection was 83.1%, compared with 69.4% fo r usual physician care (p = 0.06); the specificity values of the 2 app roaches were similar. Among patients aged 3 to 14 years, the sensitivi ty of the score approach was higher than that of usual physician care (96.9% v. 70.6%) (p < 0.05). The proportion of patients receiving init ial antibiotic prescriptions would have been reduced 48% by following score-based recommendations compared with observed physician prescribi ng (p < 0.001), without any increase in throat culture use. Conclusion s: An age-appropriate sore throat score identified GAS infection in ch ildren and adults with sore throat better than usual care by family ph ysicians, with significant reductions in unnecessary prescribing of an tibiotics. A randomized trial comparing the 2 approaches is recommende d to determine the ability of the score approach to reduce unnecessary prescribing of antibiotics during routine clinical encounters.