Tabak Ying P, Sun Xiaowu, Johannes Richard S, Gupta Vikas, Shorr Andrew F
Clinical Research Services, Cardinal Health, Marlborough, Massachusetts, USA.
Arch Intern Med. 2009 Sep 28;169(17):1595-602. doi: 10.1001/archinternmed.2009.270.
Acute exacerbations of chronic obstructive pulmonary disease (AECOPDs) often require hospitalization, may necessitate mechanical ventilation, and can be fatal. We sought to develop a simple risk score to determine its severity.
We analyzed 88,074 subjects admitted with an AECOPD between 2004 and 2006. We used recursive partition to create risk classifications for in-hospital mortality. Need for mechanical ventilation served as a secondary end point. We internally validated the model via 1000 bootstrapping on half of patients and externally validated it on the remaining patients. We assessed predictive ability using the area under the receiver operating curve (AUROC).
The in-hospital mortality rate was 2%. Three variables had high discrimination of outcomes: serum urea nitrogen level greater than 25 mg/dL (to convert to millimoles per liter, multiply by 0.357); acute mental status change, and pulse greater than 109/min. For those without any of the 3 factors, age 65 years or younger further differentiated the lowest-risk group. In those with all 3 factors, the mortality rates were 13.1% (131 in 1000) and 14.6% (146 in 1000) in the derivation and validation cohorts, respectively, compared with 0.3% (3 in 1000) in both cohorts among patients without any of the 3 factors and age 65 years or younger (P < .001). The AUROC for mortality in the 2 cohorts were 0.72 (95% confidence interval [CI], 0.70-0.74) and 0.71 (95% CI, 0.70-0.73), respectively. For mechanical ventilation, the AUROCs were 0.77 (95% CI, 0.75-0.79) for both cohorts.
A simple risk class based on clinical variables easily obtained at presentation predicts mortality and need for mechanical ventilation. It may facilitate the triage and care of patients with AECOPD.
慢性阻塞性肺疾病急性加重（AECOPD）常需住院治疗，可能需要机械通气，且可能致命。我们试图制定一个简单的风险评分来确定其严重程度。
我们分析了2004年至2006年间因AECOPD入院的88074名患者。我们使用递归划分法对住院死亡率进行风险分类。机械通气需求作为次要终点。我们通过对一半患者进行1000次自抽样在内部验证该模型，并在其余患者中进行外部验证。我们使用受试者工作特征曲线下面积（AUROC）评估预测能力。
住院死亡率为2%。三个变量对结果具有高度区分性：血清尿素氮水平大于25mg/dL（换算为毫摩尔每升时，乘以0.357）；急性精神状态改变，以及脉搏大于109次/分钟。对于没有这三个因素中任何一个的患者，65岁及以下进一步区分出最低风险组。在有所有这三个因素的患者中，推导队列和验证队列中的死亡率分别为13.1%（1000例中有131例）和14.6%（1000例中有146例），而在没有这三个因素中任何一个且年龄在65岁及以下的患者中，两个队列的死亡率均为0.3%（1000例中有3例）（P <.001）。两个队列中死亡率的AUROC分别为0.72（95%置信区间[CI]，0.70 - 0.74）和0.71（95%CI，0.70 - 0.73）。对于机械通气，两个队列的AUROC均为0.77（95%CI，0.75 - 0.79）。
基于就诊时易于获得的临床变量的简单风险分类可预测死亡率和机械通气需求。它可能有助于AECOPD患者的分诊和护理。
