Management of acute pharyngitis in adults: reliability of rapid streptococcal tests and clinical findings.

BACKGROUND How to use clinical score, the rapid streptococcal antigen test (RSAT), and culture results is uncertain for efficient management of acute pharyngitis in adults. METHODS This prospective cohort study included 372 adult patients with pharyngitis treated at a Swiss university-based primary care clinic. In eligible patients with 2 to 4 clinical symptoms and signs (temperature >or=38 degrees C, tonsillar exudate, tender cervical adenopathy, and no cough or rhinitis), we performed an RSAT and obtained a throat culture. We measured sensitivity and specificity of RSAT with culture as a gold standard and compared appropriate antibiotic use with cost per patient appropriately treated for the following 5 strategies: symptomatic treatment, systematic RSAT, selective RSAT, empirical antibiotic treatment, and systematic culture. RESULTS RSAT had high sensitivity (91%) and specificity (95%) for the diagnosis of streptococcal pharyngitis. Systematic throat culture resulted in the highest antibiotic use, in 38% of patients with streptococcal pharyngitis. Systematic RSAT led to nearly optimal treatment (94%) and antibiotic prescription (37%), with minimal antibiotic overuse (3%) and underuse (3%). Empirical antibiotic treatment in patients with 3 or 4 clinical symptoms or signs resulted in a lower rate of appropriate therapy (59%) but higher rates of antibiotic use (60%), overuse (32%), and underuse (9%). Systematic RSAT was more cost-effective than strategies based on empirical treatment or culture: 15.00 dollars, 26.00 dollars, and 32.00 dollars, respectively, per patient appropriately treated. CONCLUSIONS The RSAT we used is a valid test for diagnosis of pharyngitis in adults. A clinical approach combining this RSAT and clinical findings efficiently reduces inappropriate antibiotic prescription in adult patients with acute pharyngitis. Empirical therapy in patients with 3 or 4 clinical symptoms or signs results in antibiotic overuse.