Quantifying Tinnitus Perception Improvement: Deriving the Minimal Clinically Important Difference of the Minimum Masking Level.

Purpose: Tools that can reliably measure changes in the perception of tinnitus following interventions are lacking. The minimum masking level, defined as the lowest level at which tinnitus is completely masked, is a candidate for quantifying changes in tinnitus perception. In this study, we aimed to determine minimal clinically important differences for minimum masking level.

Method: A 3-month tinnitus intervention combining counseling and sound therapy was conducted in 74 participants with chronic tinnitus. Minimum masking levels were measured at baseline and 3 months. The clinical global impression was evaluated at 3 months to measure changes in participants' self-perception of tinnitus. The minimal clinically important difference of the minimum masking level was calculated using anchored-based, effect size, standard error measurement, and receiver operating characteristic curve analysis.

Results: The minimal clinically important difference analysis of the minimum masking level yielded a -5.5 dB SL from the receiver operating characteristic curve, a -8.1 dB SL from the standard error measurement, a -9.2 dB SL from the effect size, and a -10.3 dB SL from the anchor-based analysis. Of these, the minimal clinically important difference value with optimized sensitivity (.704) and specificity (.957) was a -5.5 dB SL, determined using receiver operating characteristic analysis.

Conclusions: The proposed minimal clinically important difference value of the minimum masking level (-5.5 dB SL) provides a good level of sensitivity and specificity. Therefore, the minimum masking level may be an alternative for measuring changes in tinnitus perception.

Supplemental material: https://doi.org/10.23641/asha.28156229.