Respiratory Epidemiology and Clinical Research Unit, Montreal Chest Institute, Montreal, Québec, Canada.
PLoS One. 2013;8(1):e54235. doi: 10.1371/journal.pone.0054235. Epub 2013 Jan 18.
Chest radiography is sometimes the only method available for investigating patients with possible pulmonary tuberculosis (PTB) with negative sputum smears. However, interpretation of chest radiographs in this context lacks specificity for PTB, is subjective and is neither standardized nor reproducible. Efforts to improve the interpretation of chest radiography are warranted.
To develop a scoring system to aid the diagnosis of PTB, using features recorded with the Chest Radiograph Reading and Recording System (CRRS).
Chest radiographs of outpatients with possible PTB, recruited over 3 years at clinics in South Africa were read by two independent readers using the CRRS method. Multivariate analysis was used to identify features significantly associated with culture-positive PTB. These were weighted and used to generate a score.
473 patients were included in the analysis. Large upper lobe opacities, cavities, unilateral pleural effusion and adenopathy were significantly associated with PTB, had high inter-reader reliability, and received 2, 2, 1 and 2 points, respectively in the final score. Using a cut-off of 2, scores below this threshold had a high negative predictive value (91.5%, 95%CI 87.1,94.7), but low positive predictive value (49.4%, 95%CI 42.9,55.9). Among the 382 TB suspects with negative sputum smears, 229 patients had scores <2; the score correctly ruled out active PTB in 214 of these patients (NPV 93.4%; 95%CI 89.4,96.3). The score had a suboptimal negative predictive value in HIV-infected patients (NPV 86.4, 95% CI 75,94).
The proposed scoring system is simple, and reliably ruled out active PTB in smear-negative HIV-uninfected patients, thus potentially reducing the need for further tests in high burden settings. Validation studies are now required.
胸部 X 光检查有时是唯一可用于调查痰涂片阴性疑似肺结核（PTB）患者的方法。然而，在这种情况下，对胸部 X 光片的解释缺乏对 PTB 的特异性，是主观的，既没有标准化，也没有可重现性。因此，有必要努力提高对胸部 X 光片的解释能力。
使用 Chest Radiograph Reading and Recording System（CRRS）记录的特征，开发一种评分系统来辅助 PTB 的诊断。
在南非的 3 年多时间里，在诊所招募了疑似患有 PTB 的门诊患者，由两名独立的读者使用 CRRS 方法对其胸部 X 光片进行阅读。多变量分析用于确定与培养阳性 PTB 显著相关的特征。这些特征被加权并用于生成评分。
纳入 473 名患者进行分析。上叶大的不透光影、空洞、单侧胸腔积液和淋巴结肿大与 PTB 显著相关，具有较高的读者间可靠性，在最终评分中分别获得 2、2、1 和 2 分。使用 2 分作为截断值，得分低于此阈值的患者具有较高的阴性预测值（91.5%，95%CI 87.1，94.7），但阳性预测值较低（49.4%，95%CI 42.9，55.9）。在 382 名痰涂片阴性的 TB 疑似患者中，有 229 名患者的评分<2；该评分正确排除了 214 名患者的活动性 PTB（NPV 93.4%；95%CI 89.4，96.3）。该评分在 HIV 感染患者中的阴性预测值不理想（NPV 86.4，95%CI 75，94）。
所提出的评分系统简单，可可靠地排除 HIV 阴性痰涂片阴性的 PTB 患者，从而有可能减少在高负担环境中进一步检查的需要。现在需要进行验证研究。
