CLINICAL DECISION RULES TO PEDIATRIC PNEUMONIA

对有下呼吸道感染（LRI）症状的患者进行胸部x线检查，主要是为了确认或排除与肺炎相符的x线浸润。然而，1995年全国健康调查显示，患有呼吸道感染的5岁以下儿童中肺炎的患病率仅约为2.8%。即使在急诊科（ED）的儿科患者中，只有7%至19%的LRI症状患者存在影像学肺炎。尽管胸片显示肺炎的比例相对较低，但许多这样的患者通常由其初级保健或急诊科医生推荐进行胸片检查。因此，患有呼吸道感染但没有影像学表现的肺炎的患者往往会发生x射线放射反应，从而导致过量辐射暴露和额外费用。关于儿童肺炎的研究已经发表了很多，但是关于如何结合病史和体格检查结果准确诊断这种疾病仍然没有共识，对于有呼吸道症状的儿童是否总是需要进行CXR诊断也没有共识。本研究的目的是制定预测2个月至59个月有LRI症状的患者影像学肺炎的决策规则。后续的研究将验证决策规则并确定应用这些规则的成本效益。本研究将于2000年10月至2001年9月在儿童医院医疗中心的急诊科进行。所有有LRI症状的患者将被纳入研究。将评估每位患者的详细病史和体格检查变量，并对所有患者进行CXR检查。每个CXR将由2名盲法放射科医生审查，并获得共识读数。与影像学肺炎密切相关的变量（p<0.05）将通过多变量技术进行分析。将制定CXR肺炎预测变量的最佳组合的决策规则。

Radiographic examination of the chest is done on patients with symptoms of a lower respiratory tract infection (LRI) primarily to confirm or exclude the presence of a radiographic infiltrate consistent with pneumonia. However, the 1995 National Health Survey showed that the prevalence of pneumonia in children under 5 years of age with respiratory infection was only approximately 2.8%. Even among pediatric patients presenting to the emergency department (ED), radiographic pneumonia was present in only 7% to 19% of patients with LRI symptoms. Despite this relatively low proportion of chest radiographs (CXRs) that reveal radiographic pneumonia, many such patients are routinely referred for a CXR by their primary care or ED physician. As a consequence, patients with respiratory infection, but without radiographic pneumonia, often have CXRs, resulting in excess radiation exposure and additional cost. Numerous studies have been published on pediatric pneumonia, however there is still no consensus opinion about how to accurately diagnose this disease based on a combination of historical and physical examination findings, nor is there agreement that a CXR is always needed to diagnose this disease in children with respiratory symptoms. The purpose of this study is to develop decision rules that will predict radiographic pneumonia in patients age 2 months to 59 months of age with symptoms of LRI. Subsequent studies will validate the decision rules and determine the cost effectiveness of applying the rules. This study will be conducted in the ED of Children's Hospital Medical Center during October 2000 through September 2001. All patients with LRI symptoms will be approached for enrollment. Detailed history and physical examination variables will be assessed on each patient and all patients will receive a CXR. Each CXR will be reviewed by 2 blinded radiologists and a consensus reading will be obtained. Variables that are strongly associated with radiographic pneumonia (p<0.05) will be analyzed by multivariate techniques. Decision rules will be developed of the best combination of predictor variables for pneumonia on CXR.