The efficiency and cost effectiveness of diagnostic tests for infectious mononucleosis.

The problem of diagnosis and appropriate treatment of patients presenting with pharyngitis is a common occurrence in family practice. The study of these patients includes laboratory tests to differentiate between infectious mononucleosis and other bacterial and viral infections. This study reviews the diagnosis of infectious mononucleosis in two large ambulatory populations, where different approaches were used. In one approach, all laboratory tests were concurrent, while in the other, serology was performed only after satisfaction of hematologic criteria for infectious mononucleosis. In the latter case, sequential use of laboratory tests resulted in a significant improvement in cost effectiveness. In both approaches, no appreciable gain was obtained from heterophil titers. Since the heterophil titer in confirmed cases of infectious mononucleosis does not correlate with prognosis or severity of the disease, this procedure can be replaced by the Monospot/"monoscreen" test alone.