198 | Chapter 8 class Correlation Coefficients (ICC) with absolute agreement and 95% confidence interval were used to determine the inter-rater reliability of the subjective voice assessments. This was done separately for the voice quality and effort to speak. An ICC of < 0 reflects ‘poor’, 0 to 0.20 ‘slight’, 0.21 to 0.4 ‘fair’, 0.41-0.60 ‘moderate’, 0.61 to 0.8 ‘substantial’ and above 0.81 ‘almost perfect’20. Device lifetime of the PVHP was calculated as day from insertion until device failure, or when no failure occurred in the twelve study months, until day of replacement.
RkJQdWJsaXNoZXIy MTk4NDMw