Naughton B J, Mylotte J M, Tayara A
Department of Medicine, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, USA.
J Am Geriatr Soc. 2000 Oct;48(10):1292-9. doi: 10.1111/j.1532-5415.2000.tb02604.x.
To derive a prediction model of 30 day mortality for nursing home-acquired pneumonia (NHAP) based on factors that can be readily identified by nursing home staff at the time of diagnosis and to apply the model to management issues related to NHAP including clarifying the importance of prepneumonia functional status as a predictor of outcome of NHAP.
This was a retrospective chart review of 378 episodes of NHAP treated in the nursing home or hospital during two periods: November 1997 to April 1998 and November 1998 to April 1999.
Eleven nursing homes in the greater Buffalo, NY region.
Nursing home residents with radiographically proven pneumonia who had at least one of the following signs/symptoms: cough, fever, purulent sputum, respiratory rate > or =25 breaths/minute, localized auscultatory findings, or pleuritic pain.
Status (alive or dead) of each resident at 30 days (30 day mortality) after diagnosis of NHAP was the dependent variable. Factors predicting 30 day mortality were identified by logistic regression analysis. A scoring system was developed based on the results of the logistic model. Each episode of NHAP in the derivation cohort was scored using the model and the cohort was stratified by the model score into six categories or risk for mortality (0-5). The predictability of the model in the derivation cohort was measured using receiver operator characteristics curve analysis.
Of 378 episodes of NHAP, 74% were treated initially in the nursing home and 26% were hospitalized initially for treatment. The overall 30 day mortality was 21.4%; however, the mortality rate was significantly higher for those treated initially in the hospital (29.6% vs 16.6%; P = .012). Logistic regression analysis identified four predictors of 30 day mortality: (1) respiratory rate >30 breaths/minute (2 points), (2) pulse > 125 beats/minute (1 point), (3) altered mental status (1 point), and (4) a history of dementia (1 point). Applying the scoring system to each episode in the derivation cohort demonstrated increasing mortality with increasing score. The c statistic for the model in the derivation cohort was .74. Based on the severity of NHAP, model episodes treated initially in the hospital were more acutely ill than those who were treated initially in the nursing home, and episodes treated with a parenteral antibiotic in the nursing home were more acutely ill than those who were treated with an oral agent. Functional status was not a predictor of 30 day mortality although there was a trend of higher mortality in the most dependent group (P = .065). The severity of NHAP model was able to define low and high risk mortality groups within a functional status category.
A severity of NHAP model was derived from a large cohort of episodes in multiple facilities. The model had reasonable discriminatory power in the derivation cohort. The model may aid clinicians in making treatment decisions in the nursing home setting and in making hospitalization decisions. Although prepneumonia functional status provides a reasonable estimate of NHAP severity and prognosis, the severity of NHAP model permitted further refinement of these estimates. The severity of NHAP model requires validation before it can be recommended for general use.
基于养老院工作人员在诊断时能够轻易识别的因素，推导养老院获得性肺炎（NHAP）30天死亡率的预测模型，并将该模型应用于与NHAP相关的管理问题，包括阐明肺炎前功能状态作为NHAP预后预测指标的重要性。
这是一项对1997年11月至1998年4月以及1998年11月至1999年4月期间在养老院或医院接受治疗的378例NHAP病例进行的回顾性病历审查。
纽约州布法罗市大区的11家养老院。
经影像学证实患有肺炎且至少有以下体征/症状之一的养老院居民：咳嗽、发热、脓性痰、呼吸频率≥25次/分钟、局限性听诊发现或胸膜炎性疼痛。
NHAP诊断后30天（30天死亡率）时每位居民的状态（存活或死亡）为因变量。通过逻辑回归分析确定预测30天死亡率的因素。根据逻辑模型的结果制定了一个评分系统。使用该模型对推导队列中的每例NHAP进行评分，并根据模型评分将队列分为六个类别或死亡风险等级（0 - 5）。使用受试者操作特征曲线分析来测量推导队列中模型的预测能力。
在378例NHAP病例中，74%最初在养老院接受治疗，26%最初住院治疗。总体30天死亡率为21.4%；然而，最初在医院接受治疗的患者死亡率显著更高（29.6%对16.6%；P = 0.012）。逻辑回归分析确定了30天死亡率的四个预测因素：（1）呼吸频率>30次/分钟（2分），（2）脉搏>125次/分钟（1分），（3）精神状态改变（1分），以及（4）痴呆病史（1分）。将评分系统应用于推导队列中的每例病例显示，随着评分增加死亡率上升。推导队列中模型的c统计量为0.74。根据NHAP的严重程度，最初在医院接受治疗的模型病例比最初在养老院接受治疗的病例病情更严重，在养老院接受胃肠外抗生素治疗的病例比接受口服药物治疗的病例病情更严重。功能状态不是30天死亡率的预测指标，尽管在最依赖组中有死亡率更高的趋势（P = 0.065）。NHAP模型的严重程度能够在功能状态类别内定义低风险和高风险死亡组。
NHAP严重程度模型源自多个机构的大量病例队列。该模型在推导队列中具有合理的鉴别能力。该模型可能有助于临床医生在养老院环境中做出治疗决策以及住院决策。尽管肺炎前功能状态可合理估计NHAP的严重程度和预后，但NHAP严重程度模型可对这些估计进行进一步细化。NHAP严重程度模型在被推荐普遍使用之前需要进行验证。
