The voice-related quality of life (V-RQOL) measure--a study on validity and reliability of the Norwegian version.

OBJECTIVES: The main purpose of this study was to evaluate the psychometric abilities of the Norwegian version of the voice-related quality of life (V-RQOL) measure. A subsidiary goal was to examine whether the formulation of two additional questions would contribute to strengthen the test.

METHODS: A total of 104 patients with voice disorders received the V-RQOL measure, voice handicap index (VHI), and a visual analog scale (VAS). Seventy-eight patients returned the forms, of which 16 were excluded because they did not meet the inclusion criteria. Analyses were carried out on 62 patients. Forty-one healthy control subjects fulfilled the V-RQOL measure, of which 36 were used in the analysis.

RESULTS: The V-RQOL measure showed a strong internal consistency (Cronbach alpha=.84-.91) and a good test-retest reliability (r=0.86-0.90). Construct validity was demonstrated with strong correlations to VHI (r=0.91) and VAS (r=0.78), together with a significant difference between patients and controls V-RQOL score. The two additional questions in the broadened version (V-RQOL12) had high mean scores (3.86 and 3.10) and strong item-total correlations (0.61 and 0.75), showing that these are important questions, measuring the same construct as the rest of the test.

CONCLUSIONS: The Norwegian version of the V-RQOL measure is a valid and reliable tool that discriminates well between voice and nonvoice patients. A broadened version of the instrument seems to strengthen the test.