Otitis media with effusion in children : frequency correlation in pure tone audiometry

Abstract

Different protocols and guidelines are adopted in clinics and countries to assess pure tone hearing sensitivity in children with otitis media with effusion (OME). The aims of the present study were (a) to investigate whether a full range of frequencies, 125 Hz to 8 kHz, is essential to evaluate hearing loss caused by otitis media with effusion in children and (b) to examine if different combinations of test frequency pure tone averaging calculations may affect recommended decision criteria for surgical treatment. Data from ninety-six children with otitis media with effusion aged 4 to 12 years who had been previously recruited for a related study was used. Right and left ear air conduction thresholds were tested from 125 Hz to 8 kHz. Paired t-tests, correlation tests (Pearson’s r, Cronbach’s alpha, and intraclass correlation) and absolute differences using Bland-Altman plots were used to examine the relationships among audiometric frequencies. Regarding the first aim of this study, only the comparison between 125 Hz and 250 Hz showed no statistically significant differences and only the comparison between 4 kHz and 8 kHz showed a clinically significant difference. When investigating individual differences, comparison between 250 Hz and 500 Hz; 125 Hz and 500 Hz; and 4 kHz and 8 kHz showed a significant number of OME ears with a clinically significant difference of ≥ 10 dB HL. Strong correlation was found in all comparisons. In the second aim of this study, the comparison between the low frequency 3 PTA average (500 Hz, 1 kHz, 2 kHz), high frequency 3 PTA average (1 kHz, 2 kHz, 4 kHz), and 4 frequency PTA average (500Hz, 1 kHz, 2 kHz, 4 kHz) showed no statistically significant differences. Correlation tests showed very strong correlation in all comparisons. Among all the combinations of PTA averages, no clinically significant differences were found in the various comparisons or within the individuals. Clinically, testing hearing sensitivity from 125 Hz to 8 kHz is necessary in evaluating hearing sensitivity in children with otitis media with effusion due to large individual variability across audiometric frequencies. Frequencies to be tested as criteria for surgical treatments of children with otitis media with effusion can be restricted to 3 frequency PTA averages, either an average of 500 Hz, 1 kHz, 2 kHz or an average of 1 kHz, 2 kHz, 4 kHz as no clinically significant differences were found within the individuals. For research purposes, 250 Hz can replace hearing thresholds at 125 Hz; and low frequency 3 PTA average (500 Hz, 1 kHz, 2 kHz), high frequency 3 PTA average (1 kHz, 2 kHz, 4 kHz) and 4 frequency PTA average (500 Hz, 1 kHz, 2 kHz, 4 kHz) can be analysed interchangeably as no statistically significant differences were found for these measures.