[Comparability and conversion of Stimmstörungsindex (SSI) and Voice Handicap Index (VHI)].

BACKGROUND: The Voice Handicap Index (VHI) has been established internationally as a reliable tool for describing voice-dependent quality of life. Nawka developed a new score by using 12 questions out of the VHI, called SSI (Stimmstörungsindex) . The SSI has proven its role in daily clinical routine, main problem remains a lack of comparability of the SSI (range: 0 - 48) to the internationally established VHI (Voice Handicap Index) (range: 0 - 120). Aim of our study was to demonstrate that by a simple multiplication of SSI scores a statistically significant correlation with scores of the VHI can be achieved.

METHODS: 210 consecutive patients of the ENT University Hospital Graz were evaluated by the German version of VHI. We calculated total score of VHI as well as the score of the SSI. By multiplication of the SSI scores by 2.5 we calculated a new score, called "VHI-korr". This score was compared with the VHI.

RESULTS: We can demonstrate that by simple multiplication of the SSI scores by 2.5 a statistically significant correlation to the VHI can be achieved (r = 0.98; p < 0.01).

CONCLUSION: The SSI- based "VHI-korr" provides good international comparability of voice disorders with VHI and allows to maintain the common use of SSI in daily clinical routine.