Fibrosis-4 score for screening of metabolic dysfunction-associated steatotic liver disease (MASLD): Data from a population-based sample in Tuscany

Background and aim: To verify the prevalence of positive Fibrosis-4 (FIB-4) score, a screening test for metabolic-associated liver disease, in a large population-based sample in the Tuscany Italian Region, and to identify sub-populations at higher risk which could be targeted by specific screening programs. Methods and results: Population-based survey performed in the Italian region of Tuscany, with Tuscany health informative system's administrative data. We included 594,923 subjects, of which 32% had available data for the FIB-4 calculation. The overall proportion of subjects with an FIB-4 value > 1.3, was 41.6% of those with available exams, and 12,8% of the whole population, whereas 5.4% and 1.7% had FIB-4 >2.67. In those younger than 80 years, FIB >1.3 had a 33.1% and 9.4%. People with diabetes mellitus had higher figures (52.8.% and 28.9% for FIB>1.3). Among subjects aged 70 years or over, 74.9% of those with available data and 38.4% of the general population had a FIB-4>1.3, whereas 32% and 16% had a FIB-4 > 2. Conclusions: The relevant proportion of FIB-4 positivity in the general population poses a significant burden for further screening with liver elastography. Targeting people with diabetes, excluding people older than 80 years and/or adopting a FIB-4 threshold of 2 in those aged more than 70 years could increase the cost-effectiveness of the screening procedures.