Research Needs: Tinnitus
The large number of interventions for tinnitus, the limitations of the existing studies, and the difficulties with assessing impact of tinnitus help us identify areas that would benefit from further study and clinical research. In general, clinical trials of interventions for tinnitus need: 1) well-defined entry criteria with regard to duration and severity of tinnitus, presence of co-morbid medical and psychiatric conditions, and the prior use of therapies, 2) use of a validated instrument to assess impact of tinnitus on QOL and daily functions as well a reliable assessment of perceived tinnitus loudness; these instruments and assessments should also reliably assess changes afforded by the treatment intervention; 3) careful selection of the placebo as well as randomization/blinding; 4) short and long term assessments; 5) adequate sample size; 6) study of a population of tinnitus patients that are representative of most patients who suffer from this symptom, to allow generalizability of results. Recommendations for future research have been made in the recent AHRQ CER and several authors have made suggestions for improvement of tinnitus trials.
The guideline development group has also suggested:
- Future clinical trials should be registered into databases such as ClinicalTrials.gov or the International Clinical Trials Registry Platform and adhere to the CONSORT Statement in order to facilitate synthesis of evidence. Adequate power should be achieved during study recruitment to detect meaningful differences in outcomes.
- Future studies of tinnitus should be methodologically enhanced in terms of reducing wide variations in patient characteristics, better defining the nature of tinnitus on entry (e.g. auditory, emotional, and attentional features), and improving uniformity in the selection of validated outcome measures in order to assess clinically relevant changes in tinnitus severity and impact. Future studies of tinnitus should use both audiologic testing and validated questionnaires for reliable and reproducible results and incorporate patient-reported outcomes with validated psychometric properties.
- Assessment of the validity and responsiveness of each of the various instruments used in tinnitus trials.
- Tinnitus trials should include a broader, more representative population of adults in terms of age, gender, and race/ethnicity in future clinical trials of tinnitus therapy.
- Future studies of tinnitus treatments should control for the use of confounding medications and other therapies that could affect the severity and perception of tinnitus.
- Inclusion of global quality-of-life (QOL) measures into clinical trials to assess how patients with tinnitus value the risk-benefit trade-off between benefits and harms of therapy.
- Determine which validated tinnitus questionnaire is most effective in assessing the severity of tinnitus effects in patients. Determine which questionnaire is most useful for assessing relevant treatment effects.
- Surveys or cohort studies are needed to determine which clinicians are approached first by patients with tinnitus (e.g. otolaryngologists, audiologists, primary care physicians, psychiatrists) (where do tinnitus patients go for initial evaluation?). Are there differences in the characteristics of tinnitus patients who see primary care providers compared to those treated by tinnitus specialists?
- Epidemiological studies are needed to establish duration/natural history of recent-onset tinnitus, determine the time to spontaneous resolution of tinnitus when this occurs.
- Documentation of the most common medical and /or psychiatric comorbidities in patients with tinnitus.
- Identification of patient subsets that respond especially well to specific treatments such as pharmacotherapy, sound therapy, etc. in open-label trials, and incorporate these specific patient subsets into subsequent RCTs.
- Conduct methodologically rigorous research into complementary and alternative medicine (CAM) therapies for tinnitus.
- Conduct surveys to determine utilization of hearing aids for tinnitus in community and academic settings, and assess the factors that could improve compliance and acceptance of hearing aids
- Conduct surveys to determine utilization of audiology evaluation for tinnitus with or without associated hearing loss.
- Conduct surveys to determine frequency of patient education and counseling for tinnitus in community and academic settings.
- Conduct studies on acamprosate, and other “promising” medical interventions, for tinnitus treatment.
- Conduct additional studies on anticonvulsant medications for tinnitus treatment.
- Conduct studies comparing the effectiveness of cognitive behavioral therapy (CBT), acceptance and commitment therapy (ACT), and bibliotherapy (i.e., providing the person with a manual on tinnitus therapy and allowing the individual to do therapy on his or her own).
- Conduct clinical trials comparing the different types of counseling treatments available for tinnitus.
- Conduct clinical trials on new therapies for tinnitus such as cochlear implantation (CI) and deep brain stimulation (DBS).
- Conduct clinical trials on auditory treatment strategies for tinnitus that could include bone conduction devices or middle ear implants.
- Conduct studies comparing the effectiveness, as well as cost-benefits, of in-person versus Internet-based CBT for tinnitus.
- Ensure that patient cohorts are stratified by concurrent depression and anxiety when conducting controlled trials of antidepressant and anxiolytic medications for tinnitus.
- Study of a variety of brain stimulation techniques, such as transcranial direct current stimulation (tDCS).
- Investigate rTMS, using stimulation schedules of longer duration, or in combination with other treatment methods (CBT, medications, etc.,) to see if more prolonged efficacy can be achieved.
- Study of acupuncture for tinnitus in a rigorous methodological approach, including the study of electroacupuncture; study of the response to acupuncture for tinnitus patients with somatic head and neck disorders.