DAS28CRP到DAS28ESR换算方程的建立和阈值的推导

Establishment of conversion equation from DAS28CRP to DAS28ESR and derivation of threshold of DAS28CRP

目的以基于ESR的28个关节疾病活动度评分(DAS28ESR)为标准,建立基于CRP的28个关节疾病活动度评分(DAS28CRP)到DAS28ESR的换算方程,并推导DAS28CRP的阈值。方法选择于中山大学孙逸仙纪念医院风湿免疫科就诊且同时测量DAS28ESR和DAS28CRP的患者。患者被随机分至训练集(70%)和验证集(30%)中。采用加权Robust回归建立DAS28CRP到DAS28ESR的换算方程,利用Wilcoxon符号秩检验比较转换值和实际值差异,采用kappa值评估疾病活动度分类一致性。结果共纳入955例患者。换算方程为DAS28ESR1=1.06×DAS28CRP+0.4275。根据换算方程,DAS28CRP相应的阈值为2.05、2.61和4.40。经过换算后,DAS28ESR转换值与实际值比较差异无统计学意义(P>0.05),且kappa值由0.54提升至0.78。结论成功建立从DAS28CRP到DAS28ESR的换算方程,这有助于不同研究间的比较,所推导出的DAS28CRP阈值有助于提高其与DAS28ESR在疾病活动度评估方面的一致性。

Objective To establish the conversion equation from DAS28CRP to DAS28ESR and derive the corresponding thresholds of DAS28CRP using DAS28ESR as the standard.Methods Patients who received simultaneous measurement of DAS28ESR and DAS28CRP at Department of Rheumatology of Sun Yat-sen Memorial Hospital were recruited and randomly assigned into the training set(70%)and validation set(30%).The Bisquare-weighted robust regression was applied to establish the conversion equation from DAS28CRP to DAS28ESR.The Wilcoxon signed-rank test was used to compare the difference between the converted values and actual values of DAS28ESR and the kappa values were used to assess the agreement in disease activity classification.Results A total of 955 patients were enrolled in the study.The conversion equation was:DAS28ESR1=1.06×DAS28CRP+0.4275.According to the conversion equation,the corresponding thresholds for DAS28CRP were 2.05,2.61 and 4.40,respectively.After conversion,there was no statistical difference between the converted values and actual values of DAS28ESR(P>0.05).The kappa values were increased from 0.54 to 0.78.Conclusions The conversion equation from DAS28CRP to DAS28ESR is successfully established,which facilitates the comparison of findings among different studies.The derived DAS28CRP thresholds contribute to improving the agreement with DAS28ESR in assessing the disease activity.