Objectives: To explore the associated factors of otitis media with effusion (OME) and analyze the diagnostic value of the adenoid-nasopharyngeal (A/N) ratio to OME.
Methods: Patients with adenoid hypertrophy (AH) recently in 2 years were collected, including sex, age, duration, with/without rhinosinusitis, and examination results, including Cone Beam Computerized Tomography (CBCT) sinus imaging, tympanometry, pure tone audiometry (PTA), blood test, and allergen detection. According to Liden/Jerger's classification, the patients were divided into two groups: Type B and type C, which were defined as the tympanometry abnormal group (TAG), and the rest were classified as the tympanometry normal group (TNG).
Results: A total of 316 children were included in this study. Age and duration were significantly younger and shorter in TAG (6.0(4.0-9.0) vs.5.0(4.0-7.0)); 12.0(4.0-24.0) vs.6.0(2.0-12.0)). Compared to TNG, the allergen test results of fx5 (protein, milk, cod, wheat, peanut, and soybean) in TAG were higher (0.09(0.04-0.25) vs.0.14(0.05-0.45)), but eosinophilia in blood was lower (count: 0.21(0.13-0.35) vs. 0.18(0.12-0.27); ratio: 3.10 (1.90-4.70) vs. 2.50 (1.65-3.80)). A/N ratio and Visual obstruction ratio had a statistical difference (Z = -3.770, P < .01) but the two ratios didn't have too much disparity (0.82(0.74-0.88) VS 0.80(0.75-0.80)), and they had a positive correlation (r = 0.345, P < .01). A/N ratio of TAG was higher than TNG (0.78(0.70-0.85) vs. 0.86(0.82-0.90)) and had a positive correlation with increasing negative middle ear pressure (r = -3.777, P < .01). A/N ratio was an associated factor of OME (OR:1355.611, P = .006), the cut-off value of A/N ratio was 0.815(sensitivity: 75.3%, specificity: 64.3%, area under the curve (AUC): 0.747).
Conclusions: A/N ratio indirectly reflected the abnormality of tympanometry in this study. When A/N ratio reaches 0.815, patients are at a higher risk of having OME so it could be a predictor of OME in patients with adenoid hypertrophy.
Keywords: adenoid hypertrophy; adenoid-nasopharyngeal ratio; allergic rhinosinusitis; otitis media with effusion.