Validation of the THI-12 questionnaire for international use in assessing tinnitus: A multi-centre, prospective, observational study

OBJECTIVE: To investigate and confirm the reliability and validity of the tinnitus handicap inventory 12 (THI-12) in various countries and languages. DESIGN: Prospective, observational study conducted in seven countries, using linguistically harmonized versions of the THI-12 in six languages. These were evaluated for test-retest reliability, internal consistency reliability, known-groups validity, and construct validity. Basic psychometric properties of supporting instruments were compared. Questionnaires were completed by the subjects at baseline and again after 12-30 days. STUDY SAMPLE: Adults with a clinical diagnosis of subjective tinnitus. RESULTS: An exploratory factor analysis of the THI-12 items for the U.S. study population at baseline revealed a single common factor of high eigenvalue. Confirmatory factor analysis supported this in the separate countries. Test-retest reliability was moderate to high, and the conclusions were supported by a known-groups analysis; correlations with other scales expected to support construct validity were moderate. CONCLUSIONS: The THI-12 total score showed acceptable psychometric properties for all countries tested. The relationships between the THI-12 and the one-month and one-week versions of the TRS and TSS were similar and convergent. The THI-12 is thus a promising diagnostic tool for assessing treatment effects in multi-cultural and multi-lingual trials on tinnitus therapy.