Exploring Research Challenges in the Study of Sudden Sensorineural Hearing Loss: An Investigation Utilizing a Large Single Clinical Practice Database.

Objectives: To analyze SSNHL patient data from a single large multi-physician institution to determine the nature of confounding factors that must be considered in designing adequate studies for improved diagnosis and treatment.

Methods: Retrospective review of a random sample of 330 patients (mean age = 61 yrs (19-96); 45% F) diagnosed with idiopathic SSNHL from 2013 to 2022 from a tertiary referral clinical practice. Data included demographics, treatment modality (oral prednisone only, intratympanic dexamethasone [IT Dex] only, or a combination of both) and regimen, time to treatment, and pure-tone averages (PTA) and word recognition scores (WRS). Different hearing outcomes were assessed, including recovery category (Complete, Partial, No Recovery) rates.

Results: Only 56% of patients had a >30 dB loss compared to the contralateral ear, while PTA and WRS both ranged widely (6 dB-NR; 0%-100%). Oral steroids were the most common treatment (83%), used alone in 32.4%, with IT Dex injections used in 68.8%, but as only treatment in 17%. 50.6% received both treatments. Hearing outcomes were generally poor, with small improvements in PTA (mean improvement = -9.5 dB, SD = 18.7) and WRS (mean improvement = 9.1%, SD = 27.7) across all subjects, with no statistically significant differences between treatment groups and a high rate of no recovery (76.2%). Pretreatment PTA followed by treatment timing (≤14 days, >14 days) and treatment type contributed significantly to predicting amount of change in PTA but accounted for only a small portion of the variability in regression analysis (R² = .232, P ≤ .001).

Conclusions: Hearing outcomes with standard steroid treatments remain suboptimal. Patients presenting for treatment of SSNHL in clinical practice can vary greatly from the formal definition of SSNHL, and past studies may not be generalizable to the overall population of patients. This highlights the challenges in defining and treating SSNHL in a clinical environment and identifies confounding factors to be considered in future research designs.