Abstract: ObjectiveTo construct a simple index instrument applicable in the screening of polypoid lesions of gallbladder(PLG) for effective treatment of PLG.MethodsA cross-sectional case-control study was conducted among 12 888 physical examinees with questionnaire survey,physical examination,abdominal ultrasound detection,and laboratory test from January through August 2014 in Xijing Hospital Affiliated to Fourth Military Medical University.ResultsOf all the participants,219 were diagnosed with PLG and the prevalence rate was 1.7%.Multivariate logistic regression analysis showed that older age,high triglyceride(TG) and high indirect bilirubin were independent risk factors for PLG; then a PLG prediction model was constructed with the three indicators:PLG index=13×age(age=1 for over 50 and age=0 for younger than 50 years)+TG+indirect bilirubin.The PLG index had an area under the receiver-operating characteristic(AUROC) curve of 0.622(95% confidence interval95%CI:0.571-0.673)in the training set and 0.615(95%CI:0.562-0.660) in the validation set.The PLG positive rate was 1.0%,1.7%,and 2.0% for the participants with the PLG index value of less than percentage of 25(P₂₅),between P₂₅-P₇₅,and greater than P₇₅,respectively.With the increment of PLG index,the positive rate of gallbladder polypoid lesions gradually increased(P<0.001).ConclusionPLG index may be significant in promoting cost-effectiveness of PLG screening and could be used to select participants for studies on effective PLG diagnosis and treatment and/or lifestyle intervention.