The Tinnitus Retraining Therapy Trial's Standard of Care Control Condition: Rationale and Description of a Patient-Centered Protocol

Reevaluating the Use of Sound Therapy for Tinnitus Management: Perspectives on Relevant Systematic Reviews

PURPOSE

Tinnitus is a highly prevalent condition that can severely reduce health functioning. In spite of extant clinical practice guidelines (CPGs), implementation of these CPGs is relatively uncommon. As a result, patients seeking professional services for tinnitus often have no assurance of receiving evidence-based care. The purpose of this tutorial was to clarify the evidence for sound therapy so that it may be included in future CPGs for tinnitus.

METHOD

"Best clinical evidence" is obtained from high-quality systematic reviews, which are generally considered the highest level of evidence. Our review of recent, comprehensive, high-quality systematic reviews of interventions for tinnitus concludes that cognitive behavioral therapy is the only effective intervention, though the strength of evidence was generally rated as low in these reviews. Although trials of sound therapy for tinnitus have been included in these reviews, they have been rated as having high risk of bias (RoB) and not included in syntheses or rated as insufficient strength of evidence.

RESULTS

Conclusions from these and other reviews have influenced recommendations made in CPGs for tinnitus. These conclusions, however, can make it appear that an intervention for tinnitus is not effective, even if the opposite is true. We contend that the strict inclusion criteria for these reviews are counterproductive and have the effect of obscuring decades of evidence demonstrating the clinical effectiveness of sound therapies for tinnitus. Ultimately, this process has resulted in many patients not receiving sound therapy, despite what should be sufficient evidence that this is an effective form of intervention.

CONCLUSION

If we rely on systematic reviews using contemporary RoB assessment criteria for studies published prior to these reporting guidelines, then we risk excluding important conclusions regarding interventions that could help patients in need.

Contributions of Counseling and Sound Generator Use in Tinnitus Retraining Therapy: Treatment Response Dynamics Assessed in a Secondary Analysis of a Randomized Trial

PURPOSE

Tinnitus retraining therapy (TRT) has been widely used for 30 years, but its efficacy and the component contributions from counseling and sound therapy remain controversial. The purpose of this secondary analysis from the Tinnitus Retraining Therapy Trial (TRTT) was to compare treatment response dynamics for TRT (counseling and conventional sound generators) with partial TRT (pTRT; counseling and placebo sound generators) and standard of care (SOC; a patient-centered counseling control).

METHOD

The TRTT randomized 151 participants with primary tinnitus (no significant hearing or sound tolerance problems) to TRT, pTRT, or SOC, each of which encouraged use of enriched environmental sound. The primary outcome, mean change in Tinnitus Questionnaire score assessed at baseline and follow-up across 18 months, was normalized for a common baseline and fitted with an exponential model. Time constants were estimated to quantify and compare the treatment response dynamics, which were evaluated for statistical significance using bootstrap analyses.

RESULTS

The change in response to TRT took less time to achieve than that for either pTRT or SOC, as demonstrated by time for normalized Tinnitus Questionnaire scores to decline to 63% and 99% of baseline TRT values: 1.2 months (95% CI [0.2, 1.9]) and 5.7 months (95% CI [0.9, 9.0]), respectively. Corresponding SOC values were 2.7 months (95% CI [1.5, 4.1]) and 12.4 months (95% CI [6.9, 19.0]), while those for pTRT were 2.2 months (95% CI [1.2, 3.4]) and 10.1 months (95% CI [5.7, 15.9]). The differences were significant for TRT versus SOC (p = .020), borderline significant for TRT versus pTRT (p = .057), but nonsignificant for pTRT versus SOC (p = .285). The magnitude of the asymptotic treatment response did not differ significantly among groups.

CONCLUSION

Sound generator use in TRT increases treatment efficiency (beyond any advantage from enriched environmental sound) without affecting treatment efficacy (determined by counseling).

The Tinnitus Retraining Therapy Counseling Protocol as Implemented in the Tinnitus Retraining Therapy Trial

Purpose This clinical focus article is a companion to the work of Erdman et al. (2019), in which we described the rationale, development, and implementation of the standard-of-care protocol used in the Tinnitus Retraining Therapy Trial (TRTT), a multicenter, placebo-controlled, randomized, definitive efficacy trial of tinnitus retraining therapy (TRT). We now describe the historical background, development, and standardized implementation and delivery of the TRT counseling protocol (tinnitus counseling [TC]) used in the TRTT. TC is conjectured to be the key component in the TRT protocol for initiating the habituation process that reduces the response to the tinnitus signal and, ultimately, reduces its impact. In the TRTT, participants assigned to receive TC achieved > 30% reduction in the impact of tinnitus. Method and Results The design and implementation of standardized treatments in multisite randomized controlled trials presents many challenges for investigators. Here, subsequent to presenting the background, rationale, and the TRT protocol model, we describe the development, refinement, and training/certification for standardized delivery of TC in the TRTT. The primary challenges encountered while distilling and streamlining TC for standardized delivery across multiple clinicians and their replacements at six participating military treatment centers in the TRTT are considered, and the resulting counseling protocol is detailed. Conclusions The standardized and streamlined TC used in the TRTT was successful for treating debilitating tinnitus among persons with functionally adequate unaided hearing sensitivity. The structured TC protocol described here appears to be the main determinant of the significant and sizable TRT treatment effects measured in the TRTT, thus bolstering the merits of this standardized counseling approach as one model for the clinical implementation of TRT for the treatment of primary tinnitus.

Treatment fidelity in the Tinnitus Retraining Therapy Trial

BACKGROUND

Treatment fidelity, defined as ensuring that the recipient receives the intended intervention, is a critical component for accurate estimation of treatment efficacy. Ensuring fidelity and protocol adherence in behavioral trials requires careful planning during the design phase and implementation during the trial. The Tinnitus Retraining Therapy Trial (TRTT) randomized individuals with severe tinnitus to tinnitus retraining therapy (TRT, comprised of tinnitus-specific educational counseling (TC) and sound therapy (ST) using conventional sound generators (SGs)); Partial TRT (TC and placebo SGs); or standard of care (SOC), using a patient-centered care approach. Study audiologists administered both types of counseling in the TRTT, creating a challenge for managing protocol adherence.

METHODS

We developed methods to enhance treatment fidelity including training, competency assessment, scripts, visual aids, and fidelity monitoring. Protocol monitors identified critical topics and content to be addressed for each type of counseling session, prepared corresponding scripts, and developed training aids and treatment-specific checklists covering those topics. Study audiologists' competency assessment required submission and review by the protocol monitors of an audiotape of one TC and one SOC counseling session. Treatment-specific aids included scripts, a 3-D model of the ear, handouts, and for TC, an illustrated flip-chart with talking points that followed the scripted content. During the trial, audiologists completed treatment-specific checklists during each counseling session, indicating topics covered/discussed and submitted audiotapes of counseling sessions. Protocol monitors reviewed audiotapes using corresponding treatment-specific checklists. Results for individual checklist items were tabulated and proportions calculated.

RESULTS

Twenty-five audiologists were certified for TC and/or SOC counseling and 24 completed at least one counseling session. Adherence to each of 33 critical items on the TC checklist as assessed by the protocol monitor ranged from 70 to 100% across 37 counseling sessions (median 97%), with no difference between adherence for TRT (median, 97%) and partial TRT (median, 100%). Adherence to each of 44 critical items on the SOC checklist across 30 SOC counseling sessions ranged from 42 to 100% (median, 87.5%).

CONCLUSION

The TRTT used multiple methods to address treatment fidelity. The close adherence to each treatment type was critical for evaluating the efficacy of the study interventions in this randomized trial.

TRIAL REGISTRATION

clinicaltrials.gov NCT01177137 . Registered on 5 August 2010.