Assessing the cost-effectiveness of antibiotic treatment of pharyngitis and acute otitis media

Abstract

Increasingly, general practitioners have to work within a limited budget for drugs and other health care activities. Program budgeting requires not only analyses of relative treatment costs and efficacies but also an assessment of the value of successful treatment outcome. Successful treatment outcome occurs when clearly defined aims of antibacterial treatment have been realized. Its value may be estimated in terms of the costs of treatment failure. It is important to understand that the aim of treatment is not always elimination of the pathogen. For example, in otitis media an imperfect relationship exists between elimination of the pathogen and clinical response, although antibiotic treatment reduces the duration and severity of acute symptoms. The costs of failed treatment of pharyngitis include the cost of additional drug therapy, plus the cost of repeat consultations, and the time spent by the physician and the patient, as well as the potential risk of acute complications such as rheumatic fever. These costs vary between countries. One method for estimating the cost of failed treatment is to generate critical minimum marginal values for improved treatment outcome, defined by the point at which the difference in drug cost is balanced by the difference in effectiveness multiplied by the cost of the treatment failure. In pharyngitis, treatment failure with traditional beta-lactam antibiotics may occur because of beta-lactamase production by normal flora in the pharynx. Failure of antibiotic treatment of pharyngitis and acute otitis media may also result from poor compliance due to low acceptability of the drug, frequent daily dosing, or prolonged treatment course. Only 20% of patients with pharyngitis have streptococcal infection, but typically, 80% of these patients are treated with antibiotics. Thus, 60% may derive no benefit. Restricting the prescribing of penicillin to patients with a high probability of bacterial infection, and using drugs such as cefixime for patients in whom penicillin treatment fails, will target the physician's resources to those patients most likely to benefit.