Effectiveness of Hearing Aid Treatment in Patients with Chronic Tinnitus: Subscale Evaluations Using the Tinnitus Functional Index and Factor Analysis

OBJECTIVES: The tinnitus functional index (TFI) is becoming a new international gold standard for tinnitus assessment. This study aimed to evaluate the efficacy of hearing aids for chronic tinnitus, using the Japanese version of the TFI, while focusing on its subscales. MATERIALS and METHODS: This is a retrospective study. A total of 21 patients with chronic tinnitus were included. All participants were treated with hearing aids for at least 12 months. They answered the TFI and tinnitus handicap inventory (THI) at the first visit and 12 months later. We analyzed each TFI subscale score and the overall scores of TFI and THI. RESULTS: The overall TFI score decreased significantly after treatment (p=0.005) with moderate effect size (d=0.70). The scores of the intrusive, sense of control, sleep, and emotional subscales decreased significantly after the treatment. Large effect sizes were found in the intrusive and sense of control subscales (d=1.33 and d=1.25, respectively). CONCLUSION: Hearing aids are highly effective for improving the intrusive and sense of control subscales in patients with tinnitus. Identifying better treatments for the small effect size subscales and combining these with the use of hearing aids could achieve a higher therapeutic effect with better outcomes.