Empirical Therapy for Respiratory Tract Infections in an Era of Increasing Antimicrobial Resistance: a Decision and Cost Analysis

BACKGROUND Acute sinusitis (or rhinosinusitis) represents one of the most common diagnoses in ambulatory care, and one of the most frequent causes for prescription of antibiotic treatment [1]. The choice of antibiotic therapy is empiric, in most cases, among agents potentially effective against the most frequently encountered upper respiratory tract pathogens, including Streptococcus pneumoniae, Haemophilus influenzae and, particularly in children, Moraxella catarrhalis [2]. Rhinosinusitis is an extremely common condition. In US health survey conducted during 2008, nearly 1 in 7 (13.4%) of all non-institutionalized adults aged 18 years were diagnosed with rhinosinusitis within the previous 12 months. Incidence rates among adults are higher for women than men (1.9-fold), and adults between 45 and 74 years are most commonly affected [3]. The prevalence of a bacterial infection during acute rhinosinusitis is estimated to be 2%–10%, whereas viral causes account for 90%–98% [4]. Despite this, antibiotics are frequently prescribed for patients presenting with symptoms of acute rhinosinusitis, being the fifth leading indication for antimicrobial prescriptions by physicians in office practice [5]. The total direct healthcare costs attributed to a primary medical diagnosis of sinusitis in 1996 were estimated to exceed $3 billion per year [6]. US survey of antibiotic prescriptions for URTIs in the outpatient setting showed that antibiotics were prescribed for 81% of adults with acute rhinosinusitis [7,8].