直接胆红素对全自动生化分析仪黄疸指数测量的影响

Effects of Direct Bilirubin on Icteric Index Detection by Automatic Biochemical Analyzer

目的评估黄疸标本直接(结合)胆红素(direct bilirubin,DBIL)比例变化对黄疸指数(icteric index,II)测量准确性的影响。方法回顾性分析北京中医药大学东方医院2021年1月至3月全部患者的总胆红素、直接胆红素和黄疸指数结果,根据直接胆红素比例将研究患者分为两组;A组直接胆红素占总胆红素百分比<50%,B组直接胆红素占总胆红素百分比≥50%。采用Spearman相关性分析和Deming(戴明)回归分析探讨两组总胆红素水平与黄疸指数的相关性并建立回归方程;Bland-Altman一致性分析用于评价两组总胆红素测量值与计算值的一致性。结果本研究包括1166名患者的胆红素和黄疸指数结果,A、B两组总胆红素水平与黄疸指数高度相关(相关系数>0.9)。Bland-Altman分析显示A组总胆红素计算值与测量值存在高度一致性,无统计学意义上的平均差异(0.005)和百分比差异(1.83%)(P>0.05);B组平均差异(27.45)和百分比差异(26.75%)具有统计学意义(P<0.05),一致性程度较差。结论本研究证实标本直接胆红素比例≥50%,黄疸指数测量的准确性会受到影响。建议临床实验室报告检验结果前严格审查黄疸指数和分析物干扰阈值。

Objective To assess the effect of changes in the ratio of direct(combined)bilirubin(DBIL)in icteric samples on the accuracy of the icteric index(II)test.Methods We retrospectively analyzed the total bilirubin,direct bilirubin,and icteric index results of all patients from January to March,2021 at the Dongfang Hospital affiliated with Beijing University of Chinese Medicine.We divided the study patients into two groups according to the percentage of direct bilirubin;group A with direct bilirubin<50%of total bilirubin and group B with direct bilirubin≥50%of total bilirubin.Spearman’s rank correlation analysis and Deming regression analysis were used to explore the correlation between the two groups’total bilirubin concentration and icteric index and to establish regression equations.Bland-Altman analysis was used to evaluate the agreement between results of the two groups’calculated and measured total bilirubin values.Results This study included bilirubin and icteric index results of 1166 patients,and the total bilirubin concentration and icteric index in groups A and B were highly correlated(correlation coefficient>0.9).Bland-Altman analysis showed a high degree of agreement between calculated and measured total bilirubin values in group A specimens,with no statistically significant mean difference(0.005)and percentage difference(1.83%)(P>0.05).In contrast,the mean difference(27.45)and percentage difference(26.75%)were significant(P<0.05)for specimens in group B,with a poor degree of agreement.Conclusion This study confirms that the accuracy of sample icteric index measurement is compromised when the direct bilirubin ratio is≥50%.It is recommended that clinical laboratories should critically review the icteric index and analyte interference thresholds before reporting test results.