Validation of the Voice Handicap Index Using Rasch Analysis

BACKGROUND: The Voice Handicap Index is a tool for measuring the psychosocial consequences of voice disorders and consists of three dimensions. Previous psychometric evaluation of the VHI focused on the classic evaluation of reliability and validity, which is sample dependent. The authors used Rasch analysis to re-examine the dimensionality of the VHI and to produce item and scale statistics that are less sample dependent. In addition, they provide estimates of VHI item and person severities that are reported on the same logit unit scale, allowing a more straightforward interpretation of a VHI test score. PATIENTS: Dysphonic patients (N = 530), who were referred for phoniatric examination, filled out the VHI. RESULTS: Rasch analysis revealed two truly uni-dimensional constructs: the 20-item psychosocial scale and the 9-item physical-functional scale. Logit item severity measures ranged from -2.1 to +2.7. Person severity scores ranged from -4.4 to + 4.4 logits. The internal consistency of the reduced scales was similar to that of the original total VHI (0.95 and 0.84). The VHI consisted of two uni-dimensional constructs. Raw test scores can be transformed into logit unit severity measures, making the VHI more suitable for evaluating the effectiveness of voice-related therapy.     

The Voice Handicap Index: Correlation Between Subjective Patient Response and Quantitative Assessment of Voice

The aim of this prospective study is to elucidate the relationship between the Voice Handicap Index (VHI) and several voice laboratory measurements in the network of the multidimensional voice assessment. Fifty-eight patients were included. Each patient replies to the questionnaire and performs a voice assessment during the same time. The following parameters were measured: minimum frequency, maximum frequency, range, minimum intensity, subglottic pressure, mean flow, maximum phonation time, jitter, and dysphonia severity index. Regarding the relationship with the scores of the VHI, poor correlations with the minimal frequency for all the scores except the emotional one (total and subscales) and with the range for only the physical one are found. Seventeen questions correlate with the voice laboratory measurements we performed, with a decreased distribution between physical, functional, and emotional subscales. We observe that acoustic parameter is correlated with the emotional subscale, the parameters of the profile range are more often involved in the emotional subscale, as is the minimal frequency, but never with the physical subscale, and all the subscales are interesting despite the smaller number of differences with the emotional one. The VHI and the laboratory measurements give independent informations in practice.