Development of the German Speech Intelligibility Index for the treatment of oral cancer patients

Abstract

ObjectivesThis study aimed at 1) adapting the well-established Speech Handicap Index (SHI) to German, 2) testing the suitability of the instrument for assessing speech-related quality of life, 3) comparing it to the German Voice-Handicap-Index (VHI), in order to support treatment of oral cancer patients who experience posttreatment speech difficulties that affect their quality of life. Material and methodsParticipants completed a web-based survey that employed a 2 (experienced problem: speech/articulation-related vs. voice-related) x 2 (SHI vs. VHI) between-subject experimental design, enabling it to distinguish between the experiences of voice and intelligibility impairments, and to determine the discriminatory ability of the two instruments. ResultsThe German SHI reliably assessed speech intelligibility and articulation-related Quality of life. While voice impairments were equally well assessed by both, VHI: M 2.48, SD 0.65; SHI: M 2.52, SD 0.63; only the latter appropriately registered intelligibility handicap in speech impairments (VHI: M 2.05, SD 0.70; SHI: 2.68, SD 0.73). The responsivity of the SHI in capturing the experienced handicap was significantly greater in the speech/articulation-impairment condition (p = .001). ConclusionThe German SHI is a reliable and responsive measure for speech intelligibility and articulation-related quality of life that should be chosen in preference to the VHI.