Analysis About Stability Of FibroTouch In Detecting Liver Stiffness Measurement And Controlled Attenuation Parameter

Objective To discuss the stability of FibroTouch(FT)in the detection of liver stiffness measurements(LSM)and controlled attenuation parameters(CAP).Methods We retrospectively collected 309 patients who underwent FT detection in the outpatient department of hepatology,the second affiliated hospital of anhui medical university from November 2018 to January 14,2019.Three different points on the same client are used to detect the FT,and the subjects were grouped according to the preliminary outpatient diagnosis,gender,age level and BMI level,respectively.We use intra-group correlation coefficient(ICC)to analyze the stability of LSM value and CAP value among different groups.Bland-Altman method was used to evaluate the stability of individual measurements.Kendall’s W test and pie chart were used to evaluate the stability of the diagnosis.Results1.The ICC of LSM and CAP values in different disease groups were > 0.75(P <0.001).The ICC of LSM value in the chronic hbv-infected group was the largest,whichwas 0.905.The ICC of CAP value in other diseases group was the largest,0.805.However,in the non-alcoholic fatty liver group,the ICC both of LSM value and the CAP value were the smallest,which were 0.785 and 0.780,respectively.The results showed that the detection values of FT had good stability in different disease groups2.The ICC value of both LSM and CAP values were>0.75(P < 0.001)in different gender groups and different age groups.However,the ICC of CAP value in female group,age ≥40 years old group was significantly lower than that in male group and age< 40 years old group.In different BMI groups,the ICC of CAP value in normal or underweight group(BMI < 24kg/㎡)is low,which was 0.671(P values < 0.001).The ICC of LSM value and CAP value in the rest groups were all > 0.75(P < 0.001).The ICC was calculated separately under different BMI,age and gender conditions.The highest ICC was found in the BMI≥24kg/㎡-< 40-male group(ICC was 0.812),and the second highest was found in the BMI≥24kg/㎡-< 40-female group(ICC was 0.729(all P values < 0.001).The lowest ICC was found in the BMI < 24kg/㎡-≥40-male group(ICC 0.574),followed by the BMI < 24kg/㎡-≥40-female group(ICC 0.688)(all P < 0.001).Except BMI≥24kg/㎡-< 40-male group of ICC > 0.75,the rest of the ICC< 0.75(P < 0.001).It indicates that age ≥40 years and BMI < 24kg/㎡ may affect the stability of CAP value in multi-point measurement.3.Bland-altman diagram was drawn between different measurement points,and all points within the consistency limit were maintained at about 95%.When the mean value of LSM of any two points is ≥10 k Pa,16.4%(9/55),13.5%(7/52)and 12%(6/50)are outside the consistency limit,which is significantly higher than the proportion of points outside the consistency limit(5.5%(17/309),4.5%(14/309)and 3.2%(10/309),respectively).When the CAP value is less than 250 d B/m,more points are outside theconsistency limit.The proportion of points outside the consistency threshold of the whole CAP was 5.8%(18/309),4.2%(13/309)and 3.6%(11/309),respectively,while the proportion outside the consistency threshold of age ≥40 years was 4.2%(13/309),1.6%(5/309)and 3.2%(10/309).4.Through analysis,Kendall’s W coefficients of LSM staging and CAP staging at three measurement points were 0.825 and 0.858,respectively(P < 0.001).The independent diagnosis of F≥ stage 2(LSM > 7.3kpa)and at least mild fatty liver stage(CAP > 240 d B/m)at the three measurement points accounted for 60% of >,while the diagnosis results at only one measurement point were consistent with the mean diagnosis results,accounting for < 10%.Conclusion The LSM value and CAP value detected by FT at different measurement points of the same patient have good stability,and the qualitative analysis of the diagnosis results of FT at different measurement points also has good stability.Older age and lower BMI may be the influencing factors for the relative instability of CAP.In order to improve the stability of F≥ stage 2 and at least reach the stage of mild fatty liver,it is recommended to take the mean value of multi-point measurement for diagnosis.