Automated Passive Case-Finding for Advanced Liver Fibrosis in MASLD: The LiverSeek Programme

LiverSeek is a fully automated, passive case-finding programme for advanced liver fibrosis associated with metabolic dysfunction-associated steatotic liver disease (MASLD) in primary care. The programme operates through the Laboratory Information System (LIS; Modulab/Biwer Analytics) of the Clinical Biochemistry Laboratory at Hospital General Universitario Gregorio Marañón (HGUGM), covering approximately 350,000 inhabitants across 11 peri-urban primary care centres affiliated to SERMAS (Servicio Madrileño de Salud) in Madrid, Spain. When a high-risk patient (age 50-75 years with ≥1 of: ALT above ULN + HbA1c ≥6.5%; ALT above ULN + BMI \>30; BMI \>30 + HbA1c ≥6.5%) undergoes a routine blood test in primary care, the LIS automatically calculates FIB-4. If FIB-4 \>1.30, the system reflexively orders ELF and MASEF from the same serum sample, without any action required from the primary care clinician. Patients with a positive second-step NIT (ELF ≥9.8 or MASEF ≥0.33) receive an automatic alert directing them to the Hepatology Advanced Practice Nurse for VCTE (FibroScan) and clinical evaluation. The primary objective is to evaluate the prevalence of hepatic fibrosis in the high-risk population using this single-step automated strategy. Secondary objectives include head-to-head diagnostic comparison of FIB-4+ELF vs FIB-4+MASEF vs FIB-4+FAST for histologically-confirmed endpoints (significant fibrosis ≥F2, advanced fibrosis ≥F3, at-risk MASH), evaluation of the Liver Risk Score, and a health-economic analysis. A sub-study evaluates a nurse-led structured lifestyle intervention in NIT-positive patients.

Inclusion Criteria: 1. Age between 50 and 75 years (inclusive) 2. Routine blood test processed in the Clinical Biochemistry Laboratory of Hospital General Universitario Gregorio Marañón, ordered by a primary care physician in one of the 11 affiliated SERMAS primary care centres 3. Presence of at least one of the following metabolic risk factor combinations: * ALT above the upper limit of normal AND HbA1c ≥6.5% * ALT above the upper limit of normal AND BMI \>30 kg/m² * BMI \>30 kg/m² AND HbA1c ≥6.5% Exclusion Criteria: 1. Age \75 years 2. Known pre-existing liver disease (significant or advanced fibrosis, cirrhosis, hepatocellular carcinoma, prior liver transplantation) 3. Prior fibrosis assessment within the preceding 12 months.