Fourie P B, Becker P J, Festenstein F, Migliori G B, Alcaide J, Antunes M, Auregan G, Beyers N, Carvalho J M, Cruz J R, Fanning E A, Gie R, Huong N D, Leitch A G
MRC National Tuberculosis Research Programme, Pretoria, South Africa.
Int J Tuberc Lung Dis. 1998 Feb;2(2):116-23.
To develop a scoring system for screening children for tuberculosis (TB) and for selecting suspects for further investigation in tuberculosis control programmes. Application of the score model, which would not require sophisticated or expensive technology, would be directed towards resource-poor countries with high prevalences of tuberculosis, where health care workers have to deal with diagnostic problems away from district hospitals or diagnostic facilities.
Based on contributions from members of an IUATLD task group from 10 countries on the use of diagnostic criteria in childhood tuberculosis, criteria were selected to be used as elements in a score model. Data were collected by standardised questionnaire on 879 subjects aged under 15 years. Of these, 794 were considered probable or confirmed cases of tuberculosis by the diagnosing doctors. From each record, the criteria/procedures used in the diagnosis of probable/confirmed TB and regarded by the doctors as relevant criteria were selected. Bacteriology, histology and chest radiography were used either singly or collectively as the definitive reference (gold standard) against which the more subjective criteria (symptoms, clinical signs, skin test) would be evaluated. The latter criteria cited as relevant were then ranked and further explored for inclusion in the score model. The relative importance of each criterion to every other criterion on the list was expressed as weights, determined by employing a logarithmic least squares method to solve the ratio scale estimation problem which underlies decision-making involving more than one criterion. The resultant values were then assigned to each criterion in the final score model.
The five clinical criteria thought to be most relevant as predictors of disease in children were history of contact with a case of tuberculosis, positive skin test, persistent cough, low weight for age, and unexplained/prolonged fever. In selecting the optimal cut-off points for the model at which tuberculosis would be suspected, low sensitivity and specificity (below 70%) but reasonably good positive predictive values (60%-77%) were obtained, depending on age group and epidemiological setting. In low tuberculosis prevalence settings, heavy reliance is placed by the model on a history of contact with a household case of tuberculosis and on a positive skin test, both of which have to be true. For high prevalence settings, more or less equal weighting is assigned to all five elements. Case contact and skin tests are less important, with low body weight, prolonged fever and cough being more indicative of tuberculosis.
The model provides for epidemiological differences between target populations and should prove successful as a screening tool to select children for further investigation by radiography and bacteriology.
制定一种评分系统，用于在结核病控制项目中筛查儿童结核病，并挑选疑似病例进行进一步调查。该评分模型的应用不需要复杂或昂贵的技术，适用于结核病高发的资源匮乏国家，在这些国家，医护人员必须在远离地区医院或诊断设施的情况下处理诊断问题。
基于国际防痨和肺部疾病联盟（IUATLD）来自10个国家的任务组成员对儿童结核病诊断标准使用情况的贡献，选择标准作为评分模型的要素。通过标准化问卷收集了879名15岁以下受试者的数据。其中，诊断医生认为794例为可能或确诊的结核病病例。从每份记录中，选择诊断可能/确诊结核病时使用的、医生认为相关的标准/程序。细菌学、组织学和胸部X线摄影单独或联合用作确定的参考标准（金标准），据此评估更主观的标准（症状、体征、皮肤试验）。然后对被列为相关的后一类标准进行排序，并进一步探讨是否纳入评分模型。每个标准相对于列表中其他标准的相对重要性以权重表示，通过采用对数最小二乘法解决涉及多个标准的决策基础的比率尺度估计问题来确定。然后将所得值分配给最终评分模型中的每个标准。
被认为最能预测儿童疾病的五个临床标准是与结核病病例接触史、皮肤试验阳性、持续咳嗽、年龄别体重低以及不明原因/长期发热。在为该模型选择怀疑结核病的最佳临界点时，根据年龄组和流行病学背景，获得了较低的敏感性和特异性（低于70%），但阳性预测值相当不错（60%-77%）。在结核病低发地区，该模型严重依赖与家庭结核病病例的接触史和皮肤试验阳性，两者都必须为真。在高发地区，对所有五个要素的权重分配或多或少相等。病例接触和皮肤试验不太重要，低体重、长期发热和咳嗽更提示结核病。
该模型考虑到了目标人群之间的流行病学差异，作为一种筛查工具，用于挑选儿童进行进一步的X线摄影和细菌学检查，应该会取得成功。
