Systematic Review of Tinnitus Biobanks and Data Repositories: Towards Harmonised Phenotyping

Background: Tinnitus affects up to 24% of older adults globally, yet its pathophysiology remains incompletely understood due to phenotypic heterogeneity and lack of standardised definitions. Biobanks offer opportunities for large-scale genetic, biomarker, and epidemiological research, but the availability and quality of tinnitus data across international repositories are unknown. By systematically identifying and characterising biobanks containing tinnitus-related data we aim to enable future collaborative research and establish recommendations for standardised phenotyping.Methods: We conducted a systematic review searching seven bibliographic databases, Google Scholar, dedicated biobank repositories, and web resources until December 15, 2025. Eligible biobanks contained tinnitus-related data from at least 500 adult participants. Independent reviewers screened records and extracted data on tinnitus definitions, sample characteristics, audiological assessments, genetic materials, biological samples, and neuroimaging availability. The protocol was pre-registered on INPLASY (INPLASY2024110063).Findings: From 12,717 initial records, we identified 56 biobanks across Europe, Asia and North America containing tinnitus data. The UK Biobank hosts the largest sample (approximately 71,547 tinnitus cases and 428,453 controls), accounting for 434 of 597 identified publications. Tinnitus definitions varied substantially across biobanks; only four (Jackson Heart Study, Maastricht Study, Rotterdam Study, Swedish Tinnitus Outreach Project) employed validated tinnitus questionnaires. Hearing assessments were available in 48 of 56 biobanks, though objective audiometry was present in only 28. Genetic material was available in 40 biobanks, biological samples in 44, and brain imaging (MRI) data in 14.Interpretation: Tinnitus is inconsistently defined across international biobanks, hampering cross-cohort analyses and genetic discoveries. We propose a minimum phenotyping dataset addressing tinnitus chronicity, severity, and comorbidities, alongside standardised audiological assessments. Harmonised data collection and collaborative analyses across biobanks could substantially advance understanding of tinnitus pathophysiology and accelerate biomarker discovery, which in turn will facilitate the development of better treatments for tinnitus.Funding: This study received no dedicated funding. Individual authors were supported by grants listed in the Acknowledgements section.