Development of an Instrument to Assess Work Productivity in Individuals With Voice Disorders: The Work Hoarse

Abstract

Objectives: Vocal function is critical to employability in the modern era. Although research clearly demonstrates that a disordered voice affects quality of life, few studies have attempted to quantitate the effects of a disordered voice on work productivity. The Voice-Related Statements battery, which originally had 20 items, was previously developed to qualitatively describe how an individual’s dysphonia affects his or her job performance. The aim of this study was to refine and reduce the item number and provide preliminary validation of this shortened instrument. Methods: The Voice-Related Statements instrument was administered to employed patients with dysphonia in conjunction with 2 additional instruments: the Voice Handicap Index (VHI) and the Work Productivity and Activity Impairment questionnaire (WPAI). Response distributions and intercorrelations were examined for item reduction. Exploratory factor analysis was conducted on retained items. Correlations were performed with other voice-related instruments. Reliability was tested using a coefficient of stability. Results: One hundred seventy-four employed patients with dysphonia were enrolled in this study. Six items were removed because of redundancy, factor analysis, and cognitive interview results. Exploratory factor analysis revealed a 1-factor structure explaining 66.28% of the total variance. The final 8-item instrument demonstrated good internal consistency (Cronbach α = 0.93), with a moderately robust correlation with the VHI ( r = 0.68, P < .001) and WPAI work impairment measures ( r = 0.63, P < .001). The VHI showed a much weaker correlation with WPAI work impairment ( r = 0.48, P < .001). Test-retest reliability was good (0.83, P < .01). Conclusions: An 8-item instrument to qualitatively measure the impact of a disordered voice at work has been developed and is called the Work Hoarse. This instrument is a better measure of voice-related work productivity impairment than the VHI and will augment quantitative work productivity instruments that are currently available.