It has been known that the diagnostic confirmation of group A streptococcal pharyngitis is accompanied with the results of throat culture and/or rapid antigen detection test(RADT). This study was designed to evaluate the usefulness and cost benefits of the RADT in patients with a sore throat compared the empirical antibiotic treated group without using RADT or throat culture with the antibiotic treated group according to the results of RADT test and/or throat culture.

From April 2003 to August 2003, total 369 patients were enrolled this study. They were redistributed into two groups. In one group, the RADT test and throat culture were used and the patients received antibiotic treatment according to the results of test and in the other group, no diagnostic examinations were used and the patients were treated with antibiotics which were chosen empirically. The flow sheet with questionnaire was drawing up and obtained the clinical symptoms, signs and the name of antibiotics that were administered.

A total of 244 patients were treated after the throat culture and/or RADT, and 125 patients were treated empirically. The prevalence of bacteriologically confirmed group A streptococcal pharyngitis was 20.1%. The sensitivity and specificity of RADT were 89.8% and 86.1%, respectively. Positive predictive value and negative predictive value were 62.0% and 97.1%, respectively. The rate of antibiotic use was high in both groups. Because the physician used the antibiotics even if the result of RADT was negative. So about 37% of reduction of antibiotics use might be possible if we used antibiotics according to the results of RADT. There were no cost differences between the RADT applied group and the empirically treated antibiotic group if we could reduce the price of RADT to 63% of the current price.

The RADT could be applied for the easy and rapid diagnosis and prompt treatment for group A streptococcal pharyngitis, and RADT could reduced the number of antibiotics used if the price of RADT was reduced to 63% of current price. For accurate evaluation of efficacy and cost effect, further controlled study is needed.