Effect of a rapid diagnostic method on prescribing patterns and ordering of throat cultures for streptococcal pharyngitis.

The sensitivity and specificity of a rapid identification test for group A beta-hemolytic streptococcus and its impact on prescribing antibiotics and ordering throat cultures were evaluated in a primary care office setting. The calculated sensitivity, specificity, positive predictive value, and negative predictive value were 82 percent, 92 percent, 76 percent, and 94 percent, respectively. Throat cultures were ordered for 98 percent of patients with acute pharyngitis regardless of the method of testing available. After use of the rapid identification test within the office, a reduction was observed in physician prescribing of antibiotics before the throat culture results were known. Physicians were more likely to initiate antibiotics immediately when rapid test results for streptococcal infection were positive and provide patient education regarding symptomatic treatment when the results were negative. The rapid identification test is an acceptable alternative to the standard culture technique in the family practice office. The rapid test was apparently responsible for the observed reduction in antibiotic prescribing and should reduce unnecessary cost and antibiotic exposure in the ambulatory setting.