Application of the fibrosis-4 score in a generalised population

Abstract

BACKGROUND

To pick up liver fibrosis, prior to presenting with cirrhosis, several different risk scores exist. One such, the fibrosis-4 (FIB-4) score, was originally validated in a population with hepatitis C and human immunodeficiency virus infection and subsequently expanded to metabolic dysfunction-associated steatotic liver disease. Local and national (British) guidelines outline when deranged liver function tests warrant calculation of a FIB-4 score.

AIM

To investigate whether the population tested with FIB-4 locally resembled the validation group/if FIB-4 was applied according to guidelines.

METHODS

All FIB-4 requests in one month from two hospitals were collected from the local laboratory system, along with laboratory and demographic data. The data collected were narrowed down to those that matched the initial validation population’s laboratory values from 2006. The group was then further narrowed down to exclude patients dissimilar to the validation population (using electronic medical records to exclude based on age, obesity, and other factors as outlined by the original study from which the FIB-4 score originates).

RESULTS

It was found that the vast majority of patients having a FIB-4 calculated were grossly dissimilar to the initial population on which the score was originally validated, and the patients who did resemble it often had a FIB-4 calculated even if there was no apparent indication to do so.

CONCLUSION

There are multiple compounding factors of error in indiscriminate use of FIB-4. Probability of liver steatosis would likely be better assessed by using adaptations of the score on appropriate populations.

Keywords: Risk assessment; Liver fibrosis; Fatty liver; Non-alcoholic fatty liver disease; Metabolic dysfunction-associated steatotic liver disease

Core Tip: The fibrosis-4 (FIB-4) score is used indiscriminately and when applied inappropriately may lead to misleading results and diagnostic noise. This study shows how different a generalised population is from the population on which the FIB-4 score was validated. Other adaptations of the FIB-4 score exist that have shown diagnostic superiority on specific populations which could be applied, even reflexively using artificial intelligence.