Eichenfield A H, Athreya B H, Doughty R A, Cebul R D
Pediatrics. 1986 Sep;78(3):480-4.
Rheumatoid factor is commonly used by clinicians to assess children with possible juvenile rheumatoid arthritis. To assess its usefulness, we reviewed the case histories of patients in whom latex agglutinating rheumatoid factor was determined during 1981 to 1982 at our institution. A total of 437 charts were available for review. There were 11 patients with positive tests for rheumatoid factor, of whom five had juvenile rheumatoid arthritis, all polyarticular. A total of 426 children had negative results, of whom 100 had juvenile rheumatoid arthritis. This yields a sensitivity of 4.8% and a specificity of 98%. We then estimated the prevalence of juvenile rheumatoid arthritis in three clinical settings: a primary practitioner's office, a tertiary children's hospital walk-in clinic, and a pediatric rheumatology center. The predictive values and marginal benefits for rheumatoid factor were then calculated in those settings using Bayes' theorem. In the two general outpatient settings, the primary practitioner's office and tertiary walk-in clinic, the positive predictive values were 0.7% and 0.5%, respectively; marginal benefits were 0.4% and 0.3%, respectively. Rheumatoid factor testing appeared to be of some benefit in the pediatric rheumatology center with a positive predictive value of 72.5% and marginal benefit of 22.5%. In no case was rheumatoid factor testing helpful in establishing a diagnosis of juvenile rheumatoid arthritis or in ruling it out. Testing for rheumatoid factor is a poor screening procedure for juvenile rheumatoid arthritis in the general situations in which it is more likely to be requested and of supportive diagnostic value only in the highly restricted population of older children with polyarticular arthritis.
类风湿因子常用于临床医生评估可能患有幼年类风湿关节炎的儿童。为评估其效用，我们回顾了1981年至1982年在我们机构测定乳胶凝集类风湿因子的患者病历。共有437份病历可供查阅。类风湿因子检测呈阳性的患者有11例，其中5例患有幼年类风湿关节炎，均为多关节型。共有426名儿童检测结果为阴性，其中100例患有幼年类风湿关节炎。这得出的敏感度为4.8%，特异度为98%。然后我们估计了在三种临床环境中幼年类风湿关节炎的患病率：基层医疗医生办公室、三级儿童医院的门诊诊所和儿科风湿病中心。然后在这些环境中使用贝叶斯定理计算类风湿因子的预测值和边际效益。在两个普通门诊环境，即基层医疗医生办公室和三级门诊诊所中，阳性预测值分别为0.7%和0.5%；边际效益分别为0.4%和0.3%。类风湿因子检测在儿科风湿病中心似乎有一定益处，阳性预测值为72.5%，边际效益为22.5%。在任何情况下，类风湿因子检测都无助于确立或排除幼年类风湿关节炎的诊断。在更可能被要求检测类风湿因子的一般情况下，它对幼年类风湿关节炎而言是一种欠佳的筛查程序，仅在患有多关节型关节炎的大龄儿童这一高度受限人群中具有辅助诊断价值。
