Background The effect of the skin–capsular distance (SCD) on the controlled attenuation parameter (CAP) for diagnosis of liver steatosis in patients with nonalcoholic fatty liver disease (NAFLD) remains unclear. Methods The SCD was measured using B-mode ultrasound, and the CAP was measured using the M probe of FibroScan®. According to the indications of the M probe, 113 patients with an SCD of ≤ 25 mm were included in the present study. The association between the SCD and CAP was investigated, and the diagnostic performance of the SCD-adjusted CAP was tested. Results The SCD showed the most significant positive correlation with the CAP (ρ = 0.329, p < 0.001). In the multiple regression analysis, the SCD was associated with the CAP independent of pathological liver steatosis. The adjusted CAP was calculated as follows: adjusted CAP (dB/m) = CAP − (5.26 × SCD). The area under the receiver operating characteristic curve for diagnosis of a steatosis score ≥ 2 was significantly greater for the adjusted CAP than original CAP. Conclusions The SCD is associated with the CAP independent of liver steatosis. Adjustment of the CAP using the SCD improves the diagnostic performance of the CAP in NAFLD.

A 2-step approach, Fibrosis-4 index (FIB-4) followed by vibration-controlled transient elastography (VCTE), has been proposed to predict advanced fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). We aimed to develop a novel 3-step approach for predicting advanced fibrosis. We enrolled 284 biopsy-confirmed NAFLD patients from two tertiary care centers and developed subgroups (n = 190), including 3.7% of patients with advanced fibrosis, assuming a primary care setting. In the 3-step approach, patients with intermediate-to-high FIB-4 in the first step underwent an enhanced liver fibrosis (ELF) test or measurement of type IV collagen 7S domain (T4C7S) as the second step, and VCTE was performed if the second step value was higher than the cutoff. In 284 cases, a tertiary care cohort with 36.3% advanced fibrosis, the 3-step approach showed significantly higher specificity and positive predictive value than the 2-step approach. In the subgroup with 3.7% advanced fibrosis, the 3-step approach significantly reduced the referral rate to specialists, the number of high-risk patients (i.e., liver biopsy candidates), and healthcare costs by 12.5–15.8%. The 3-step approach may improve the diagnostic performance to predict advanced fibrosis in NAFLD, which could lower rates of referrals to specialists, liver biopsies, and medical costs.