Screening the General Population for Non-Alcoholic Fatty Liver Disease: Model Development and Validation

Abstract

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide. Screening the general population for this may help to select appropriate diagnostic and preventive measures before disease progression. We aimed to develop a screening method to identify patients with NAFLD in the general population. We analyzed cross-sectional data from a large Japanese study of NAFLD. Principal component analysis was used to analyze the data. Candidate predictors were patients' demographic, clinical, and laboratory characteristics. The resulting model was externally validated using three data sets from different populations. Of 15,464 (54.5% men) included patients, 2,741 (17.7%) had NAFLD as determined by ultrasonography. An index was calculated as the arithmetic mean of the scaled body mass index and serum triglyceride levels for both men and women. The area under the receiver operating characteristic curve, sensitivity, specificity, and false positive rate were 0.875, 0.824, 0.770, and 17.6%, respectively. The mean index values were significantly different between the patients with and without non-alcoholic fatty liver disease (p <0.001). The odds ratio of the index cutoff was 15.6 (95% confidence interval [CI]:14.05, 17.39). The model yielded areas under the curve of 0.828, 0.851, and 0.836 for a Chinese (N = 2,319), an Iranian (N = 2,160), and a Brazilian (N = 45,029) data set, respectively. The proposed composite index demonstrated high performance and generalizability, suggesting its potential use as a screening tool for NAFLD in the general population.