Non-invasive fibrosis scores are widely used to identify/exclude advanced fibrosis in patients with non-alcoholic fatty liver disease (NAFLD).
However, these scores were principally developed and validated in patients aged between 35 and 65 years of age.
Dr Stuart McPherson and colleagues from the United Kingdom assessed the effect of age on the performance of non-invasive fibrosis tests in NAFLD.
Patients were recruited from European specialist hepatology clinics.
The researchers divided the cohort into 5 age-based groups, including 35 years or younger, 36–45 years, 46–55 year, 56–64 years, and 65 years or more.
|New cutoffs for those aged 65 years or more improved specificity to 70%|
|American Journal of Gastroenterology|
The team evaluated the performance of the aspartate aminotransferase (AST)/alanine transaminase (ALT) ratio, fibrosis 4, and NAFLD fibrosis score for advanced fibrosis for each group was assessed using liver biopsy as the standard.
The research team included 634 patients.
The diagnostic accuracy of the AST/ALT ratio was lower than NAFLD fibrosis score, and fibrosis 4 in all the age groups.
The AST/ALT ratio, NAFLD fibrosis score, and fibrosis 4 score performed poorly for a diagnosis of advanced fibrosis in those aged 35 years or less.
For all groups 35 years or older, area under the received of operating curves for advanced fibrosis were similar for the NAFLD fibrosis score, and fibrosis 4 score.
The researchers found that the specificity for advanced fibrosis using the fibrosis 4 and NAFLD fibrosis score declined with age, becoming unacceptably low in those aged 65 years or older.
The research team derived new cutoffs for those aged 65 years or more, which improved specificity to 70% without adversely affecting sensitivity.
Dr McPherson's team concludes, "The NAFLD fibrosis score and fibrosis 4 scores have similar accuracy for advanced fibrosis in patients aged more than 35 years."
"However, the specificity for advanced fibrosis is unacceptably low in patients aged 65 years or older, resulting in a high false positive rate."
"New thresholds for use in patients aged 65 years or older are proposed to address this issue."