(110) The Inadequacy of Targeted Hearing Screening for Children with Cystic Fibrosis

Background: Patients with cystic fibrosis (CF) are at an increased risk for sensorineural hearing loss (SNHL) presumably from exposure to potentially ototoxic medications such as aminoglycosides and macrolides. We sought to determine the percentage of CF patients who underwent audiologic testing when there was a concern for hearing loss and risk factors associated with the development of SNHL.

Methods: A retrospective study of a large number of patients with CF was performed to determine the rate of hearing evaluation and risk factors for SNHL. Audiometric results, medication history, and hospitalization history were recorded. Descriptive statistics were calculated to compare the measures of those with SNHL and those without SNHL. For the purpose of this study, SNHL was defined as a hearing threshold >25 dB HL at one or more frequencies, 0.25-18 kHz.

Results: Three hundred thirty CF patients were evaluated at a single Children’s Hospital from January 2014 through December 2019. Audiometric testing was documented in 112 patients. Two patients were excluded from the data analysis due to an alternative diagnosis known to cause hearing loss. Those who underwent aminoglycoside therapy (p< 0.001), and a hospitalization for CF related treatment (p< 0.001) were more likely to undergo hearing testing. However, 146 out of 218 (67%) patients who did not undergo hearing testing had a history of aminoglycoside exposure and 110 out of 218 (50.4%) who were hospitalized for a CF related condition did not undergo hearing testing. There was no statistically significant difference in those who underwent audiologic testing based on age, CF mutation, gender or ethnicity.

The mean age of first audiologic test was 8±5 years of age. Thirteen out of one hundred-ten CF patients (11.8%) were diagnosed with SNHL at one of more frequencies. All patients with CF and hearing loss had on average elevated hearing thresholds at all measured frequencies compared to those without hearing loss. This difference was most noticeable at extended high frequencies (i.e. ≥ 14 kHz). Interestingly, 5 patients (38.5%) had a hearing loss between 250 and 8 kHz without evidence of loss at extended high frequencies. When evaluating for risk factors, there was no statistically significant difference between those with and without SNHL based on age, aminoglycoside exposure, hospitalization, CF mutation, gender, or ethnicity.

Conclusions: This study indicates that a risk-based approach for hearing testing may overlook many CF children at risk to develop SNHL. These results underscore the need for a standardized protocol to evaluate the prevalence of SNHL in all children with CF. Increased awareness and regular hearing evaluations incorporating traditional and extended high frequency audiometry should be a part of the standard of care for these patients.

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