Liver fibrosis is a serious, life-threatening condition. It develops due to liver tissue scarring, which results from the accumulation and concentration of insoluble collagen and extracellular matrix. This scarring process evolves through distinct stages and is triggered by chronic liver damage [1]. If not diagnosed on time, liver fibrosis can lead to other advanced liver problems such as cirrhosis and hepatocellular carcinoma (HCC). Cirrhosis is the final stage of hepatic fibrosis in which the liver tissue is irreversibly damaged, and it is impossible to regenerate and remove the scar tissue, unlike in earlier stages [2].

Cirrhosis affects one in every 400 adults in the United States, with a higher prevalence among those aged 45 to 54. Additionally, the global prevalence of cirrhosis is estimated to be between 4.5 % and 9.5 % [3], [4]. In 2015, the global disability-adjusted life year (DALY) rate of chronic liver disease was 565 per 100,000, and the number of years lost due to disease (YLL) was 558 per 100,000 [5].

The gold-standard method for diagnosing liver fibrosis is Liver biopsy. However, numerous other less invasive diagnostic and grading procedures have been created. Non-invasive approaches include ultrasonography and elastography, and blood tests, such as blood platelet count and liver enzymes, including aspartate aminotransferases (AST) and alanine aminotransferases (ALT), have been proven to be relatively accurate [6], [7]. The fibrosis-4 (FIB-4) index is one of the tools to estimate the risk of liver fibrosis based on age, ALT level, AST level, and platelet count. It is a cost-effective option compared to other non-invasive markers, largely due to the fact that the FIB-4 parameters are routinely included in standard liver disease assessments [8].

Given the poor prognosis and potential complications associated with advanced-stage liver fibrosis, it is important to assess the risk factors linked to the development of liver fibrosis. Several risk factors have previously been linked to the development of liver fibrosis. Male gender, older age, high body mass index, high AST level, albumin concentration, diabetes mellitus, low platelet (PLT) count, alcohol consumption, elevated diastolic blood pressure, and smoking can all be risk factors for liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis B [7], [8]. It is necessary to learn more about the factors contributing to the progression of chronic liver disease into fibrosis and its severity, especially given the vast knowledge gap in Iran. This study aimed to assess the prevalence of liver fibrosis in the Pars cohort study and the potential associated factors for developing liver fibrosis using the FIB-4 classification. The findings of this study can be used to create more effective screening protocols for the early detection of liver fibrosis, allowing practitioners to begin therapeutic interventions before the onset of cirrhosis. These findings may also be useful in developing general, occupational, and nutritional health policies and evaluating the burden of liver fibrosis in future studies.