Call for an Evidence-Based Consensus on Outcome Reporting in Tinnitus Intervention Studies

Comparing Clustering Methods Applied to Tinnitus within a Bootstrapped and Diagnostic-Driven Semi-Supervised Framework

The understanding of tinnitus has always been elusive and is largely prevented by its intrinsic heterogeneity. To address this issue, scientific research has aimed at defining stable and easily identifiable subphenotypes of tinnitus. This would allow better disentangling the multiple underlying pathophysiological mechanisms of tinnitus. In this study, three-dimensionality reduction techniques and two clustering methods were benchmarked on a database of 2772 tinnitus patients in order to obtain a reliable segmentation of subphenotypes. In this database, tinnitus patients’ endotypes (i.e., parts of a population with a condition with distinct underlying mechanisms) are reported when diagnosed by an ENT expert in tinnitus management. This partial labeling of the dataset enabled the design of an original semi-supervised framework. The objective was to perform a benchmark of different clustering methods to get as close as possible to the initial ENT expert endotypes. To do so, two metrics were used: a primary one, the quality of the separation of the endotypes already identified in the database, as well as a secondary one, the stability of the obtained clusterings. The relevance of the results was finally reviewed by two ENT experts in tinnitus management. A 20-cluster clustering was selected as the best-performing, the most-clinically relevant, and the most-stable through bootstrapping. This clustering used a T-SNE method as the dimensionality reduction technique and a k-means algorithm as the clustering method. The characteristics of this clustering are presented in this article.

Content validity of the tinnitus outcome questionnaire for sound management

Standardized instruments are often used to monitor one’s progress in tinnitus relief although they were developed to screen and diagnose tinnitus. The need for the development for a tinnitus outcome assessment tool is high in the field of audiology and otolaryngology. The purpose of this study was to develop a tinnitus outcome questionnaire for sound management (listening to sound stimuli for tinnitus relief) and assess its content validity. A total of 32 questions with six domains (Tinnitus characteristics, the impact of tinnitus, tinnitus and hearing issues, handedness, tinnitus management, and sound management outcome) were generated after closely investigating major tinnitus questionnaires used worldwide (i.e. Tinnitus Handicap Inventory and Tinnitus Handicap Questionnaire) as well as literature. Ten healthcare professionals evaluated the appropriateness of the questionnaire items on a five-point Likert scale, where 1 is strongly inappropriate and 5 is strongly appropriate. Content relevance was assessed by computing the content validity index with the cut-off value of 0.75. Each response was first weighted as follows: 1 = 0; 2 = 0.25; 3 = 0.5; 4 = 0.75; and 5 = 1.0. The weighted average was then calculated. Items with a content validity index less than 0.75 were discarded and some items were revised according to the experts’ feedback. As a result, 31 out of the 32 items had the content validity index higher than 0.75, indicating that the items are appropriate to obtain information about the six domains. Reflecting the experts’ feedback, some questions were revised to be more specific. The study provides a baseline structure regarding potential questions to be included in a tinnitus outcome questionnaire for sound management. Development and standardization of such questionnaire would be a pathway to validating tinnitus relief via sound therapy.

All for One and One for All? - Examining Convergent Validity and Responsiveness of the German Versions of the Tinnitus Questionnaire (TQ), Tinnitus Handicap Inventory (THI), and Tinnitus Functional Index (TFI)

BACKGROUND

Measurement of tinnitus-related distress and treatment responsiveness is key in understanding, conceptualizing and addressing this often-disabling symptom. Whilst several self-report measures exist, the heterogeneity of patient populations, available translations, and treatment contexts requires ongoing psychometric replication and validation efforts.

OBJECTIVE

To investigate the convergent validity and responsiveness of the German versions of the Tinnitus Questionnaire [TQ], Tinnitus Handicap Inventory [THI], and Tinnitus Functional Index [TFI] in a large German-speaking sample of patients with chronic tinnitus who completed a psychologically anchored 7-day Intensive Multimodal Treatment Programme.

METHODS

Two-hundred-and-ten patients with chronic tinnitus completed all three questionnaires at baseline and post-treatment. Intraclass correlation coefficients determined the convergent validity of each questionnaire's total and subscale scores. Treatment responsiveness was investigated by [a] comparing treatment-related change in responders vs. non-responders as classified by each questionnaire's minimal clinically important difference-threshold, and [b] comparing agreement between the questionnaires' responder classifications.

RESULTS

The total scores of all three questionnaires showed high agreement before and after therapy (TQ | THI: 0.80 [Pre], 0.83 [Post], TQ | TFI: 0.72 [Pre], 0.78 [Post], THI | TFI: 0.76 [Pre] 0.80 [Post]). All total scores changed significantly with treatment yielding small effect sizes. The TQ and TFI yielded comparable (19.65 and 18.64%) and the THI higher responder rates (38.15%). The TQ | THI and TQ | TFI showed fair, and the THI | TFI moderate agreement of responder classifications. Independent of classification, responders showed significantly higher change rates than non-responders across most scores. Each questionnaire's total change score distinguished between responders and non-responders as classified by the remaining two questionnaires.

CONCLUSION

The total scores of all three questionnaires show high convergent validity and thus, comparability across clinical and research contexts. By contrast, subscale scores show high inconsistency. Whilst the TFI appears well suited for research purposes, the THI may be better suited to measure psychological aspects of tinnitus-related distress and their changes with accordingly focused treatment approaches.

How to Interpret Tinnitus Functional Index Scores: A Proposal for a Grading System Based on a Large Sample of Tinnitus Patients

OBJECTIVES

The Tinnitus Functional Index (TFI) is considered the gold standard in measuring tinnitus severity. The aim of the study was to establish reference values to improve the interpretability of TFI scores.

DESIGN

Results from 1114 patients with tinnitus were retrospectively analyzed. The participants were consecutive patients who attended our tertiary referral Ear, Nose, and Throat Center. The eligibility criteria were: at least 18 years old, persistent tinnitus, completed pure-tone audiometry, and answered all 25 items on the TFI. Hearing status (normal hearing vs. hearing impairment) was established according to the recommendation of the Bureau International d'Audiophonologie. Means (M) and SD on the TFI were the basis for grading tinnitus severity on four levels: low, lower moderate, upper moderate, and high. To gauge individual scores in clinical practice, percentiles are also proposed.

RESULTS

All 1114 patients (586 women and 528 men) were Caucasian and aged from 19 to 87 years (M = 50.96; SD = 13.10 years). Tinnitus duration ranged from 0.5 to 50 years (M = 7.17; SD = 7.71 years). There were 258 patients with normal hearing and 856 patients with hearing loss. A score of above 65 points on TFI was established as the cutoff point for diagnosing high tinnitus severity. A regression model associating tinnitus severity with gender, age, tinnitus duration, and hearing loss was statistically significant: F(4,1109) = 8.99; p < 0.001, but the effect was very small (R2adj = 0.028) and only gender and age were associated with TFI global score, while tinnitus severity was not related to tinnitus duration or hearing loss.

CONCLUSIONS

The reference values proposed here support those reported previously by Meikle et al. They are empirically based and can be used as benchmarks in clinical practice and scientific research. They make it possible to assess tinnitus severity, evaluate individual scores, and categorize individuals with tinnitus. This allows researchers to set inclusion or exclusion criteria when assigning patients to specific groups during clinical trials involving tinnitus intervention strategies.

A portable neurofeedback device for treating chronic subjective tinnitus: Feasibility and results of a pilot study

BACKGROUND

Several clinical studies have shown that neurofeedback (NFB) has the potential to significantly improve the quality of life of patients complaining of chronic subjective tinnitus. Yet the clinical applicability of such a therapeutic approach in the everyday practice has not been tested so far.

OBJECTIVE

This study aims at investigating the feasibility and efficacy of a semi-automated NFB intervention by means of a portable device that eventually could be used by the patients at home on an everyday basis. The duration of setup procedures is minimized through the use of a dry electrodes electroencephalography (EEG) headset and an automated user-interface.

METHODS

We conducted a pilot clinical study (non-controlled, single arm, NCT03773926). According to a predetermined power calculation, a homogeneous population of 33 subjects with strict inclusion criteria was enrolled. After inclusion, all patients underwent 10 NFB sessions lasting 50min each, over a period of 5 weeks and a 3-month follow-up period. According to previous studies, the NFB training aimed at increasing the alpha-band power (8-12Hz) in the EEG power spectrum on the averaged signal of leads FC1, FC2, F3 and F4. Tinnitus handicap inventory (THI) was used as a primary outcome measure. Secondary outcome measures were the visual analog scales (VAS) and the change of the alpha-band power within sessions and across training. Time points of assessment were before intervention (T1), after intervention (T2) and at the 3-month follow-up (T3).

RESULTS

Patient exhibited a clinically significant decrease of the THI score, with a 23% decrease (N=28) on average between T1 and T2 and a 31% decrease (N=25) between T1 and T3. A significant increase of the alpha-band power within sessions was observed. No significant increase of the alpha-band power across sessions was observed. For the 19 subjects where sufficient data were exploitable, a significant correlation was found between the evolution of the alpha-band training across sessions and the evolution of the THI between T1 and T2. The sessions were well tolerated and no adverse effect was reported.

CONCLUSION

This study suggests that neurofeedback has potential to suit everyday clinical practice with the goal to significantly reduce tinnitus intrusiveness. The merits and limitations of this NFB procedure are discussed, especially with respect to the choice of EEG electrodes to ensure a good signal quality.

Avenue for Future Tinnitus Treatments

Tinnitus is a common symptom. Standard therapies aim at improving the quality of life and reducing the psychological stress associated with tinnitus. Most interventions have little or no effect on the main symptom. Those affected subjects, however, want such a change and prefer a specific solution, such as pharmacologic therapy to other modalities. Scientific efforts have not yet led to significant improvement in the range of therapies. This article outlines existing efforts and develops ideas on how research for improved tinnitus therapy might look in the future.

How Do We Know That Our Patients Have Benefitted From Our ENT/Audiological Interventions? Presented at the Annual Meeting of ADANO 2016 in Berlin

: This short review article gives an introduction to some of the fundamental concepts and challenges facing measurement in hearing healthcare practice and research. The impact of hearing loss almost always extends beyond the sensory impairment itself, even when the measured degree of audiometric loss is mild. Yet, going beyond audibility, into the realm of measuring impact, takes us into a much more complex and less well-defined space. How does one therefore best measure the therapeutic benefit for evaluating efficacy or for clinical practice audit? Three case studies illustrate approaches to overcome such challenges. Each example highlights the importance of thinking critically about what it is one is seeking trying to measure, rather than selecting a questionnaire instrument based simply on its popularity or accessibility. We conclude by highlighting the important role that clinicians can play in collecting clinical data about their preferred instruments so that we have some evidence to inform decisions about good practice (content validity etc.). We would also strongly support open data sharing as we think that this is one of the best ways to make the most rapid progress the field.

Assessing the Heterogeneity of Complaints Related to Tinnitus and Hyperacusis from an Unsupervised Machine Learning Approach: An Exploratory Study

Introduction: Subjective tinnitus (ST) and hyperacusis (HA) are common auditory symptoms that may become incapacitating in a subgroup of patients who thereby seek medical advice. Both conditions can result from many different mechanisms, and as a consequence, patients may report a vast repertoire of associated symptoms and comorbidities that can reduce dramatically the quality of life and even lead to suicide attempts in the most severe cases. The present exploratory study is aimed at investigating patients’ symptoms and complaints using an in-depth statistical analysis of patients’ natural narratives in a real-life environment in which, thanks to the anonymization of contributions and the peer-to-peer interaction, it is supposed that the wording used is totally free of any self-limitation and self-censorship. Methods: We applied a purely statistical, non-supervised machine learning approach to the analysis of patients’ verbatim exchanged on an Internet forum. After automated data extraction, the dataset has been preprocessed in order to make it suitable for statistical analysis. We used a variant of the Latent Dirichlet Allocation (LDA) algorithm to reveal clusters of symptoms and complaints of HA patients (topics). The probability of distribution of words within a topic uniquely characterizes it. The convergence of the log-likelihood of the LDA-model has been reached after 2,000 iterations. Several statistical parameters have been tested for topic modeling and word relevance factor within each topic. Results: Despite a rather small dataset, this exploratory study demonstrates that patients’ free speeches available on the Internet constitute a valuable material for machine learning and statistical analysis aimed at categorizing ST/HA complaints. The LDA model with K = 15 topics seems to be the most relevant in terms of relative weights and correlations with the capability to individualizing subgroups of patients displaying specific characteristics. The study of the relevance factor may be useful to unveil weak but important signals that are present in patients’ narratives. Discussion/Conclusion: We claim that the LDA non-supervised approach would permit to gain knowledge on the patterns of ST- and HA-related complaints and on patients’ centered domains of interest. The merits and limitations of the LDA algorithms are compared with other natural language processing methods and with more conventional methods of qualitative analysis of patients’ output. Future directions and research topics emerging from this innovative algorithmic analysis are proposed.

One Size Does Not Fit All: Developing Common Standards for Outcomes in Early-Phase Clinical Trials of Sound-, Psychology-, and Pharmacology-Based Interventions for Chronic Subjective Tinnitus in Adults

Good practice in clinical trials advocates common standards for assessing and reporting condition-specific complaints ("outcome domains"). For tinnitus, there is no common standard. The Core Outcome Measures in Tinnitus International Delphi (COMiT'ID) study created recommendations that are relevant to the most common intervention approaches for chronic subjective tinnitus in adults using consensus methods. Here, the objectives were to examine why it is important to tailor outcome domain selection to the tinnitus intervention that is being evaluated in the clinical trial and to demonstrate that the COMiT'ID recommendations are robust. The COMiT'ID study used an online three-round Delphi method with three separate surveys for sound-, psychology-, and pharmacology-based interventions. Survey data were analyzed to assess quality and confidence in the consensus achieved across surveys and stakeholder groups and between survey rounds. Results found participants were highly discriminatory in their decision-making. Of the 34 outcome domains reaching the prespecified consensus definition in the final round, 17 (50%) were unique to one intervention, while only 12 (35%) were common to all three. Robustness was demonstrated by an acceptable level of agreement across and within stakeholder groups, across survey rounds, across medical specialties (for the health-care practitioners), and across health-care users with varying tinnitus duration. There were few dissenting voices, and results showed no attrition bias. In conclusion, there is compelling evidence that one set of outcomes does not fit all therapeutic aims. Our analyses evidence robust decisions by the electronic Delphi process, leading to recommendations for three unique intervention-specific outcome domain sets. This provides an important starting point for standardization.

Tinnitus Severity Change Following Stapedotomy in Patients With Otosclerosis

OBJECTIVE

To determine whether stapedotomy was effective in reducing tinnitus severity. In addition, the relationship between reduction in tinnitus and improvement in hearing after stapedotomy was analyzed.

STUDY DESIGN

Prospective clinical study.

SETTING

Tertiary referral center.

PATIENTS

A group of 168 otosclerosis patients diagnosed with chronic tinnitus.

INTERVENTION

Stapedotomy.

MAIN OUTCOME MEASURES

The Tinnitus Functional Index questionnaire (TFI) was used to assess tinnitus severity before surgery, and at 3 and 6 months postoperatively. Pure-tone audiometry was conducted before surgery and 6 months postoperatively.

RESULTS

The TFI Total score before the operation was M = 34.5 (standard deviation [SD] = 1.6) points, and decreased 3 months after stapedotomy to M = 17.5 (SD = 1.7), a statistically significant change (T = -8.200; p < 0.001). A weak correlation was found between the pre- and postoperative difference of TFI Total score and air-conduction thresholds (r = 0.21; p = 0.013) as well as between the TFI Total score and the size of the air-bone gap (r = 0.21; p = 0.013). Preoperatively, 86 patients tinnitus was a not or small problem, and for 82 it was moderate to very big. After stapedotomy, 93 (55%) of patients experienced a significant reduction in tinnitus severity. Of the whole group, 62 patients (37%) reported complete disappearance of their tinnitus. No change in tinnitus severity was reported by 63 patients (38%), and an increase was observed by 12 patients (7%).

CONCLUSION

Stapedotomy not only improves hearing but also reduces tinnitus severity. The current results extend knowledge of postoperative results in terms of tinnitus severity, and might benefit patients undergoing tinnitus counseling. It might also be useful to otolaryngologists when making decisions regarding qualification criteria.

Designing Clinical Trials for Assessing the Effectiveness of Interventions for Tinnitus

In the face of finite resources, allocations of research and health-care funding are dependent upon high-quality evidence. Historically, tinnitus has been the poor cousin of hearing science, with low-quality clinical research providing unreliable estimates of effect and with devices marketed for tinnitus without strong evidence for those product claims. However, the tinnitus field is changing. Key opinion leaders have recently made calls to the field to improve the design, implementation, and reporting of clinical trials, and there is growing intersectoral collaboration. The Tonndorf Lecture presented at the 1st World Tinnitus Congress and the 12th International Tinnitus Seminar in Warsaw, Poland, provided an opportunity to reflect on the present and future progress of tinnitus research and treatment and what is needed for the field to achieve success. The content of that lecture is summarized in this article. The main debate concerns the selection and reporting of outcomes in clinical trials of tinnitus. Comprehensive reviews of the literature confirm the diversity of the personal impact of tinnitus and illustrate a lack of consensus in what aspects of tinnitus should be assessed and reported in a clinical trial. An innovative project is described which engages the global tinnitus community (patients and professionals alike) in working together. This project seeks to improve future tinnitus research by creating an evidence-based consensus about minimum reporting standards for outcomes in clinical trials of a tinnitus intervention. The output will be a core set of important and critical outcomes to be measured and reported in all clinical trials.

Therapeutic Approaches to the Treatment of Tinnitus

Tinnitus is a highly prevalent condition that is associated with hearing loss in most cases. In the absence of external stimuli, phantom perceptions of sounds emerge from alterations in neuronal activity within central auditory and nonauditory structures. Pioneering studies using lidocaine revealed that tinnitus is susceptible to pharmacological interventions. However, lidocaine is not effective in all patients, and no other drug has been identified with clear efficacy for the long-term treatment of tinnitus. In this review, we present recent advances in tinnitus research, including more detailed knowledge of its pathophysiology and involved neurotransmitter systems. Moreover, we summarize results from animal and clinical treatment studies as well as from studies that identified tinnitus as a side effect of pharmacological treatments. Finally, we focus on challenges in the development of pharmacological compounds for the treatment of tinnitus, namely the limitations of available animal models and of standardized clinical research methodologies.

Recruiting and retaining participants in e-Delphi surveys for core outcome set development: Evaluating the COMiT'ID study

Background

A Core Outcome Set (COS) is an agreed list of outcomes that are measured and reported in all clinical trials for a particular health condition. An ‘e-Delphi’ is an increasingly popular method for developing a COS whereby stakeholders are consulted via a multi-round online survey to reach agreement regarding the most important outcomes. Many COS studies seek diverse, international input that includes professionals and healthcare users. However, the recruitment and retention of participants can be deterred by various factors (e.g. language barriers and iterative, time-consuming rounds). This report evaluates the effectiveness of recruitment and retention methods used in the Core Outcome Measures in Tinnitus International Delphi (COMiT’ID) study using participant feedback from healthcare users, healthcare practitioners, researchers, commercial representatives and funders.

Methods

A range of methods were applied to recruit participants to the study and maintain engagement over the three rounds. Feedback on recruitment and retention methods was collected using a twenty-item online questionnaire, with free text comments.

Results

A personalised email invitation was the most frequent recruitment route, and 719 professionals and healthcare users consented to take part. Retention of each stakeholder group ranged from 76 to 91% completing all three e-Delphi rounds. Feedback was given by 379 respondents. A majority of respondents were satisfied with the study methods that were implemented to promote retention. Over 55% indicated that their overall experience closely matched their expectations at the start of the study, and over 90% felt that their contribution was appreciated.

Conclusions

This report highlights study methods that worked well with respect to recruitment and retention, and those that did not. Findings provide a unique contribution to the growing evidence base of good practice in COS development by demonstrating the relative effectiveness of recruitment and retention methods for an e-Delphi survey.

Trial registration

This project was registered (November 2014) in the database of the Core Outcome Measures in Effectiveness Trials (COMET) initiative. The protocol is published in Trials (doi:10.1186/s13063-017-2123-0).

Defining and evaluating novel procedures for involving patients in Core Outcome Set research: creating a meaningful long list of candidate outcome domains

PLAIN ENGLISH SUMMARY

Outcome domains are aspects of a condition that matter to patients and clinicians and can be measured to assess treatment effects. For tinnitus, examples include 'tinnitus loudness' and 'ability to concentrate'. This study focuses on the first stage of agreeing which outcome domains should be measured in all clinical trials of tinnitus. Crucially, it involves identifying outcome domains, prior to a voting process. This article describes how we effectively involved patients in that study design process, and reflects on the impact of their input.The study first compiled a long list of all possible outcome domains before asking interested parties, including patients, to vote which ones to include. Ensuring patients fully participate in this process holds unique challenges as it can be long, repetitive and its purpose far removed from their needs. These challenges may be addressed by involving patients in designing the research. There is evidence that other research teams are doing this, but its reporting is not detailed enough to guide others. Our paper seeks to address this.We describe how we involved patients (people living with tinnitus) in creating a long list of outcome domains that we included in our study. We also reflect on the benefits this brought. Two patients partnered with us in designing the survey. We also consulted an independent patient review panel. Involving patients reduced the list of domains included in the survey and made domain names and associated descriptions clearer. Our resulting survey performed well in recruiting and retaining patients as participants.

ABSTRACT

Background Tinnitus is a complex audiological condition affecting many different domains of everyday life. Clinical trials of tinnitus interventions measure and report those outcome domains inconsistently and this hinders direct comparison between study findings. To address this problem, an ongoing project is developing a Core Outcome Set; an agreed list of outcome domains to be measured and reported in all future trials. Part of this project uses a consensus methodology ('Delphi' survey), whereby all relevant stakeholders identify important and critical outcome domains from a long list of candidates. This article addresses a gap in the patient involvement literature by describing and reflecting on our involvement of patients to create a meaningful long list of candidate outcome domains.Methods Two Public Research Partners with lived experience of tinnitus reviewed an initial list of 124 outcome domains over two face-to-face workshops. With the Study Management Team, they interpreted each candidate outcome domain and generated a plain language description. Following this, the domain names and descriptions underwent an additional lay review by 14 patients and 5 clinical experts, via an online survey platform.Results Insights gained from the workshops and survey feedback prompted substantial, unforeseen modifications to the long list. These included the reduction of the number of outcome domains (from 124 to 66) via the exclusion of broad concepts and consolidation of equivalent domains or domains outside the scope of the study. Reviewers also applied their lived experience of tinnitus to bring clarity and relevance to domain names and plain language descriptions. Four impacts on the Delphi survey were observed: recruitment exceeded the target by 171%, there were equivalent numbers of patient and professional participants (n = 358 and n = 312, respectively), feedback was mostly positive, and retention was high (87%).Conclusions Patient involvement was an integral and transformative step of the study design process. Patient involvement was impactful because the online Delphi survey was successful in recruiting and retaining participants, and there were many comments about a positive participatory experience. Seven general methodological features are highlighted which fit with general principles of good patient involvement. These can benefit other Core Outcome Set developers.

The COMiT'ID Study: Developing Core Outcome Domains Sets for Clinical Trials of Sound-, Psychology-, and Pharmacology-Based Interventions for Chronic Subjective Tinnitus in Adults

Subjective tinnitus is a chronic heterogeneous condition that is typically managed using intervention approaches based on sound devices, psychologically informed therapies, or pharmaceutical products. For clinical trials, there are currently no common standards for assessing or reporting intervention efficacy. This article reports on the first of two steps to establish a common standard, which identifies what specific tinnitus-related complaints ("outcome domains") are critical and important to assess in all clinical trials to determine whether an intervention has worked. Using purposive sampling, 719 international health-care users with tinnitus, health-care professionals, clinical researchers, commercial representatives, and funders were recruited. Eligibility was primarily determined by experience of one of the three interventions of interest. Following recommended procedures for gaining consensus, three intervention-specific, three-round, Delphi surveys were delivered online. Each Delphi survey was followed by an in-person consensus meeting. Viewpoints and votes involved all stakeholder groups, with approximately a 1:1 ratio of health-care users to professionals. "Tinnitus intrusiveness" was voted in for all three interventions. For sound-based interventions, the minimum set included "ability to ignore," "concentration," "quality of sleep," and "sense of control." For psychology-based interventions, the minimum set included "acceptance of tinnitus," "mood," "negative thoughts and beliefs," and "sense of control." For pharmacology-based interventions, "tinnitus loudness" was the only additional core outcome domain. The second step will next identify how those outcome domains should best be measured. The uptake of these intervention-specific standards in clinical trials will improve research quality, enhance clinical decision-making, and facilitate meta-analysis in systematic reviews.