Rapid Strep Test Most Cost-effective for Pharyngitis Workup in Adults

[Admin]

March 31, 2006 — Performing a rapid streptococcal antigen test (RSAT) on all adults who present with acute pharyngitis and initiating antibiotic therapy for positive results is the most cost effective way to manage this common problem, new research suggests.

Roughly 10% of acute pharyngitis cases are due to a bacterial pathogen, most commonly group A beta-hemolytic streptococci. Although such cases are the only ones that warrant antibiotics, up to 73% of all patients with pharyngitis receive antibiotics anyway.

The optimal management of acute pharyngitis in adults is unclear, lead author Dr. Jean-Paul Humair from the University Hospital of Geneva and colleagues note. "There is no evidence-based consensus on the best clinical approach."

The gold standard for diagnosing group A streptococcal pharyngitis is throat culture, "despite its suboptimal performance, cost, and delayed results in clinical practice," according to the report in the Archives of Internal Medicine for March 27. While RSAT-based management could represent a more cost-effective alternative, recent studies have favored a culture-based approach over RSAT-based management or empirical treatment.

To investigate this topic further, Dr. Humair's team compared five management strategies in 372 adult patients with pharyngitis at a university-based clinic in Switzerland.

The five strategies included: 1. symptomatic treatment without testing or antibiotic therapy; 2. systematic RSAT with antibiotic therapy in patients with positive results; 3. selective RSAT in patients with two or three clinical criteria and empirical antibiotic therapy in patients with four criteria; 4. empirical antibiotic therapy without testing in patients meeting three or four clinical criteria; 5. systematic culture with antibiotic treatment in patients with positive results.

RSAT was 91% sensitive and 95% specific in diagnosing streptococcal pharyngitis, the report indicates.

The systematic culture approach yielded a 100% appropriate treatment rate, but it was also the most costly strategy at $32.40 per case appropriately treated. The systematic RSAT approach was the second most accurate method with a slightly lower appropriate treatment rate — 93.8% — but the cost was much less, $15.30 per case appropriately treated.

The other management strategies had lower appropriate treatment rates and, except for the symptomatic treatment approach, were more costly than the systematic RSAT approach.

A clinical approach based on systematic RSAT is the most cost-effective way to "limit antibiotic prescription and to appropriately treat acute pharyngitis in adults," the authors conclude.

Arch Intern Med. 2006;166:640-644

Source: http://www.medscape.com/viewarticle/528883?src=mp