Outcomes of clinical trial: tinnitus masking versus tinnitus retraining therapy.

A controlled clinical study was conducted to evaluate prospectively the clinical efficacy of tinnitus masking (TM) and tinnitus retraining therapy (TRT) in military veterans having clinically significant tinnitus. Qualifying patients were placed into the two groups in an alternating manner (to avoid selection bias), and treatment was administered at 0, 3, 6, 12, and 18 months. Outcomes of treatment were evaluated using three self-administered tinnitus questionnaires (Tinnitus Handicap Inventory, Tinnitus Handicap Questionnaire, Tinnitus Severity Index) and the verbally administered TRT interview forms. Findings are presented from the three written questionnaires, and from two of the interview questions (percentage time aware of, and annoyed by, tinnitus). Outcomes were analyzed on an intent-to-treat basis, using a multilevel modeling approach. Of the 123 patients enrolled, 118 were included in the analysis. Both groups showed significant declines (improvements) on these measures, with the TRT decline being significantly greater than for TM. The greater declines in TRT compared to TM occurred most strongly in patients who began treatment with a "very big" tinnitus problem. When patients began treatment with a "moderate" tinnitus problem, the benefits of TRT compared to TM were more modest.