Liver stiffness evaluation is usually considered as reliable when it fulfills criteria of having 10 or more valid measurements, 60% or more success rate, and interquartile range / median ratio (IQR/M) of 0.30 or less.
However, such reliable liver stiffness evaluation have never been shown to be more accurate than unreliable liver stiffness evaluation.
Dr Jérôme Boursier and colleagues evaluated the relevance of the usual definition for LSE reliability, and improved reliability by using diagnostic accuracy as a primary outcome in a large population.
The team included 1,165 patients with chronic liver disease from 19 French centers.
All patients had liver biopsy and liver stiffness evaluation.
|Well-classified patients for the diagnosis of cirrhosis was 90% for the 'very reliable group'|
The research team noted that 76% of liver stiffness evaluation were reliable according to the usual definition.
However, these reliable liver stiffness evaluation were not significantly more accurate than unreliable liver stiffness evaluation.
In multivariate analyses with different diagnostic targets, liver stiffness evaluation median and IQR/M were independent predictors of fibrosis staging, with no significant influence of 10 or more valid measurements, or liver stiffness evaluation success rate.
These 2 reliability criteria determined 3 liver stiffness evaluation groups, including 'very reliable', 'reliable', and 'poorly reliable'.
The team found that rates of well-classified patients for the diagnosis of cirrhosis were, respectively, 90%, 86%, and 70%.
According to these new reliability criteria, 9% of liver stiffness evaluation were poorly reliable, 74% were reliable, and 17% were very reliable.
Dr Boursier's team concludes, "The usual definition for liver stiffness evaluation reliability is not relevant."
"Liver stiffness evaluation reliability depends on IQR/M according to liver stiffness median level, defining thus 3 reliability categories, including very reliable, reliable, and poorly reliable liver stiffness evaluation."