Hearing impairment and ototoxic medication exposure in children with cystic fibrosis: a multicenter cross-sectional study

Purpose To estimate the prevalence of hearing impairment and explore its associations with demographic, clinical, and medication-use characteristics in Iranian children and adolescents with cystic fibrosis (CF). Methods This multicenter cross-sectional study included 193 participants younger than 18 years before age rounding with a documented clinical diagnosis of CF in Lorestan, Kerman, and Khuzestan during 2023–2024. Hearing status was obtained from audiological reports under an operational ≥30 dB definition. Medication use was recorded as binary indicators without route-specific or cumulative exposure information. Group comparisons used exact conditional Wilcoxon rank-sum and Fisher exact tests. Exploratory associations were estimated using univariable Firth penalized logistic regression. Results Median age was 12.00 years (IQR, 11.00–14.00), and 107 participants (55.4%) were female. Six participants had hearing impairment, giving a prevalence of 3.1% (exact 95% CI, 1.1%–6.6%); all six were classified as having mild sensorineural loss. Impairment occurred in 6 of 64 participants with tobramycin use and none of 129 without use. The Firth estimate suggested an association (OR, 28.78; profile penalized-likelihood 95% CI, 3.31–3776.23; P < 0.001), with substantial imprecision. The azithromycin comparison was inconclusive. Conclusion Hearing impairment was uncommon under the study definition. The exploratory, unadjusted tobramycin association does not establish causation or a route-specific effect. Larger prospective multicenter studies with detailed medication exposure histories and baseline and repeated hearing assessments are needed.