Studies of microorganisms involved in otitis media in children often use a nasopharyngeal sample as a proxy for the middle ear fluid to test for bacteria and viruses. The question is whether such studies provide an accurate estimate of the prevalence of microorganisms involved in otitis media. We performed a systematic review of the literature reporting on the concordance between test results of nasopharyngeal and middle ear fluid samples for the most prevalent microorganisms in children with otitis media. Our findings show that the concordances vary from 68% to 97% per microorganism. For the most prevalent microbes, positive predictive values are around 50%. Most negative predictive values are moderate to high, with a range from 68% up to 97%. These results indicate that test results from nasopharyngeal samples do not always provide an accurate proxy for those of the middle ear fluid. It is important to interpret and use results of such studies carefully.
From the Departments of *Epidemiology, Julius Center for Health Sciences and Primary Care, †Otorhinolaryngology, Division Surgical Specialities and ‡Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, The Netherlands; and §ENT Clinical Trials Programme, Ear Institute, University College London, United Kingdom.
Accepted for publication November 29, 2012.
A.G.M.S. has received an honorarium from GlaxoSmithKline (Rixensart, Belgium) for participating in educational activities and workshops related to pneumococcal vaccination and otitis media. She has received funds from GlaxoSmithKline for research on microbial pathogens in acute tympanostomy tube otorrhea. The authors have no other funding or conflicts of interest to disclose.
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Address for correspondence: Thijs M. A. van Dongen, MD, Julius Center for Health Sciences and Primary Care, STR 6.131, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands. E-mail: firstname.lastname@example.org.