A revised grading system for the Tinnitus Handicap Inventory based on a large clinical population.

Objective: Tinnitus Handicap Inventory (THI) is one of the world's most commonly used tools to assess tinnitus severity. The aim of the current study was to establish a revised THI grading system using standard Z-scores and percentiles.Design: Cross-sectional observational study.Study sample: Adult patients (1042 participants - 518 (49.7%) female and 524 (50.3%) male) reporting tinnitus duration of a minimum of 6 months with complete documentation on patient's clinical status (age, gender, tinnitus duration and laterality, tinnitus handicap based on THI and hearing status based on pure-tone audiometry) were included in the study.Results: Multivariate analysis of variance was used to analyse the effects of gender and hearing loss on THI scores and revealed there was a significant effect of both. Consequently, separate grading systems for women and men, as well as for subjects with normal hearing and hearing loss, is proposed.Conclusions: Our findings are generally consistent with existing grading. Normative values proposed for THI scores, based on a large group of tinnitus patients, could be useful to guide decisions about appropriate intervention options or to evaluate treatment outcomes.