BACKGROUND: Tinnitus is the perception of sound without an external auditive stimulus and can be a severe burden for affected patients. Medical guidelines recommend cognitive behavioral therapy (CBT) for tinnitus treatment, which effectively improves tinnitus-related distress and anxiety. OBJECTIVE: This study investigates the outcome of a 9-month smartphone-based CBT for patients with tinnitus. METHODS: The randomized controlled clinical trial in this study investigates the efficacy of a smartphone-based CBT for 187 patients with chronic tinnitus over a 9-month treatment period. In the initial 3 months, a waiting list design was applied, and in the subsequent study phase, the data of both treatment groups were collectively analyzed. The scores on the Tinnitus Questionnaire (TQ)
9-item Patient Health Questionnaire (PHQ-9)
9-item Self-Efficacy, Optimism, Pessimism (SWOP-K9) questionnaire
and 20-item Perceived Stress Questionnaire (PSQ-20) were assessed as endpoints after 3 and 9 months of treatment. RESULTS: We observed a statistically significant reduction in the tinnitus burden in patients who received the smartphone-based CBT intervention. Although no changes were observed initially in the TQ sum scores in the waiting control group (baseline mean, 37.8, SD 4.7
3 months mean 37.5, SD 4.8
analysis of covariance [ANCOVA] P=.52), the scores significantly decreased once the app-based CBT had commenced. Data pooled from both groups revealed significant reduction in the TQ sum score by 12.49 (SD 1.44) (ANCOVA, P<
.001) and 18.48 (SD 1.85) (ANCOVA, P<
.001) points after 3 and 9 months, respectively, which was also clinically important. The calculated Cohen d was 1.38. Similarly, the scores on PSQ-20 (-9.14 points
ANCOVA, P<
.001), PHQ-9 (-2.47 points
ANCOVA, P<
.001), and SWOP-K9 (0.17 points
ANCOVA, P<
.001) were significantly improved at the end of the therapy, with corresponding intermediate effect sizes after 9 months. CONCLUSIONS: The data in our study provide evidence of statistically significant, clinically relevant, and continuous benefits of an app-based CBT intervention in patients with chronic tinnitus. TRIAL REGISTRATION: Deutsches Register Klinischer Studien DRKS00022973
https://drks.de/search/de/trial/DRKS00022973.