de Punder Yvonne M R, van Riel Piet L C M, Fransen Jaap
From the Department of Rheumatology, Radboud University Medical Centre, Nijmegen, the Netherlands.Y.M.R. de Punder, MD; P.L.C.M. van Riel, MD, PhD, Professor of Rheumatology; J. Fransen, PhD, Department of Rheumatology, Radboud University Medical Centre.
J Rheumatol. 2015 Mar;42(3):391-7. doi: 10.3899/jrheum.140327. Epub 2015 Jan 15.
To compare the performance of an extended model and a simplified prognostic model for joint damage in rheumatoid arthritis (RA) based on 3 baseline risk factors: anticyclic citrullinated peptide antibodies (anti-CCP), erosions, and acute-phase reaction.
Data were used from the Nijmegen early RA cohort. An extended model and a simplified baseline prediction model were developed to predict joint damage progression between 0 and 3 years. Joint damage progression was assessed using the Ratingen score. In the extended model, prediction factors were positivity for anti-CCP and/or rheumatoid factor, the level of erythrocyte sedimentation rate, and the quantity of erosions. The prediction score was calculated as the sum of the regression coefficients. In the simplified model, the prediction factors were dichotomized and the number of risk factors was counted. Performances of both models were compared using discrimination and calibration. The models were internally validated using bootstrapping.
The extended model resulted in a prediction score between 0 and 5.6 with an area under the receiver-operation characteristic (ROC) curve of 0.77 (95% CI 0.72-0.81). The simplified model resulted in a prediction score between 0 and 3. This model had an area under the ROC curve of 0.75 (95% CI 0.70-0.80). In internal validation, the 2 models showed reasonably well the agreement between observed and predicted probabilities for joint damage progression (Hosmer-Lemeshow test p > 0.05 and calibration slope near 1.0).
A simple prediction model for joint damage progression in early RA, by only counting the number of risk factors, has adequate performance. This facilitates the translation of the theoretical prognostic models to daily clinical practice.
基于抗环瓜氨酸肽抗体（抗CCP）、骨侵蚀和急性期反应这3个基线风险因素，比较类风湿关节炎（RA）关节损伤扩展模型和简化预后模型的性能。
使用奈梅亨早期RA队列的数据。开发了一个扩展模型和一个简化的基线预测模型，以预测0至3年期间的关节损伤进展。使用拉廷根评分评估关节损伤进展。在扩展模型中，预测因素为抗CCP和/或类风湿因子阳性、红细胞沉降率水平以及骨侵蚀数量。预测分数计算为回归系数之和。在简化模型中，将预测因素进行二分法处理并计算风险因素数量。使用区分度和校准对两个模型的性能进行比较。通过自抽样对模型进行内部验证。
扩展模型的预测分数在0至5.6之间，受试者操作特征（ROC）曲线下面积为0.77（95%CI 0.72 - 0.81）。简化模型的预测分数在0至3之间。该模型的ROC曲线下面积为0.75（95%CI 0.70 - 0.80）。在内部验证中，这两个模型相当好地显示了关节损伤进展的观察概率与预测概率之间的一致性（Hosmer-Lemeshow检验p>0.05且校准斜率接近1.0）。
早期RA关节损伤进展的简单预测模型，仅通过计算风险因素数量，就具有足够的性能。这有助于将理论预后模型转化为日常临床实践。
