Prognostic model for predicting hearing recovery in idiopathic sudden sensorineural hearing loss.

HYPOTHESIS

To aid in realistic counseling of patients at the time of their first visit concerning their chances for recovery, we created a simple prognostic model for predicting hearing recovery in idiopathic sudden sensorineural hearing loss (ISSHL).

BACKGROUND

An important element of research on ISSHL is to identify prognostic factors for this disease. Many studies have described predictive indicators to identify patients with a good prognosis needing no or minimal treatment. Only a few of these studies have included a model for calculating the probability for patient recovery, which may be important for clinical work, but these prognostic tables have not achieved widespread use clinically.

METHODS

Evaluation of an electronic patient data base of 541 patients with ISSHL. The standard treatment was carbogen inhalation (95% O2 and 5% CO2 8 times per day in duration of 30 min) and prednisone orally (100 mg in 1 morning dose) for 7 days. Factors that were analyzed included the patient's age, the interval between the onset of symptoms and beginning of treatment, the presence or absence of vertigo and tinnitus, audiometric patterns, the severity of hearing loss, and hearing in the opposite ear. Hearing gain was expressed either as absolute hearing gain or as relative hearing gain. Significant recovery of hearing was defined as the final pure-tone audiometry of 30 dB or less (or the same as the pure-tone audiometry of the opposite ear).

RESULTS

The absolute hearing gain was 15.1 dB. The mean relative hearing gain was 47%. Three hundred one (57%) patients had significant recovery of hearing, and 228 (43%) did not have significant recovery of hearing. Using step-wise multiple linear regression analysis, the most important factors for prognosis included severity of hearing loss, presence of vertigo, time between onset and treatment, the hearing of the other ear, and the audiogram shape (beta coefficient was -0.216, -0.231, 0.211, 0.113, and -0.064, respectively; constant, 0.968). A recovery expectancy table was developed using the data from this study.

CONCLUSION

Based on a retrospective analysis, prognostic indicators for hearing recovery in ISSHL were found to be severity of hearing loss, presence of vertigo, time between onset and treatment, the hearing of the other ear, and the audiogram shape. We created a model for calculating the probability for hearing recovery based on the analysis of 529 patients with unilateral ISSHL.