# Establishing a core domain set for early-phase clinical trials of electrical stimulation interventions for tinnitus in adults: an online Delphi study

## TL;DR

This study created a standard set of outcomes to measure in clinical trials of electrical stimulation treatments for tinnitus, ensuring consistent evaluation across future research.

## Contribution

The study introduces a core domain set for evaluating electrical stimulation interventions for tinnitus, achieved through stakeholder consensus.

## Key findings

- Stakeholders reached consensus on five core domains: ability to ignore, concentration, treatment satisfaction, helplessness, and tinnitus intrusiveness.
- Adverse effects were also included as a critical domain for evaluation in clinical trials.
- The core domain set aims to standardize reporting and improve comparability of research findings.

## Abstract

Tinnitus is the awareness of sound in the ear or head in the absence of an external source. It affects around 10%–15% of people, and current treatment options are limited. Experimental treatments include various forms of electrical stimulation of the brain. Currently, there is no consensus on the outcomes that should be measured when investigating the efficacy of this type of intervention for tinnitus.

This study sought to address this issue by establishing a core domain set: a common standard of what specific tinnitus-related complaints are critically important to assess in all clinical trials of electrical stimulation-based interventions for tinnitus.

A two-round Delphi survey was conducted, followed by a stakeholder consensus meeting to identify a core domain set.

Setting

All data collection took place online

Participants represented one of two stakeholder groups: patients with lived experience of tinnitus and professionals with relevant clinical, commercial or research experience.

Stakeholders achieved consensus on the inclusion of ability to ignore, concentration, treatment satisfaction, helplessness (lack of control) and tinnitus intrusiveness in the core domain set, in addition to adverse effects.

This study established a core domain set for the evaluation of electrical stimulation-based interventions for tinnitus via an e-Delphi study. This core domain set will act as a minimum standard for reporting in future clinical trials of electrical stimulation interventions for tinnitus. Standardisation will facilitate comparability of research findings.