Jointly modelling the relationship between survival and pulmonary function in cystic fibrosis patients
Jointly modelling the relationship between survival and pulmonary function in cystic fibrosis patients
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DOI：
10.1002/sim.1104
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发表时间：
2002-05-15
影响因子：
2
通讯作者：
Davis, PB
中科院分区：
文献类型：
--
作者：
Schluchter, MD;Konstan, MW;Davis, PB
肺功能与囊性纤维化（CF）生存率之间关系的建模因以下事实而变得复杂：常用的肺功能测量（如一秒用力呼气量（FEV1））测量存在误差，肺功能最差的患者越来越多地通过死亡进行审查，即数据仅适用于存活至当前年龄的患者。我们假设FEV1预测百分比的线性随机效应模型，其中FEV1预测百分比的随机截距和斜率以及死亡年龄的指定转换沿着遵循三变量正态分布。我们说明了如何使用这个模型来描述死亡年龄和参数的个体患者的FEV1预测百分比与年龄的回归之间的关系，如斜率和截距或FEV1预测百分比的真实值在给定的年龄。我们还说明了该模型如何提供这些单个参数的经验贝叶斯估计。特别是，我们探讨如何预测值的死亡年龄可能被用作预后或严重程度指数。该模型和方法在188名囊性纤维化患者的群组上进行说明，所述囊性纤维化患者具有共同的基因型（对于DeltaF508突变是纯合的），出生于1965年或之后，并且在美国俄亥俄州克利夫兰市彩虹婴儿和儿童医院的CF中心进行随访。
Modelling the relationship between pulmonary function and survival in cystic fibrosis (CF) is complicated by the fact that measures of pulmonary function commonly used such as the forced expiratory volume in one second (FEV1) are measured with error, and patients with the poorest lung function are increasingly censored by death, that is, data are available only for the patients who have survived to the current age. We assume a linear random effects model for FEV1 per cent predicted, where the random intercept and slope of FEV1 per cent predicted, along with a specified transformation of the age at death follow a trivariate normal distribution. We illustrate how this model can be used to describe the relationship between age at death and parameters of the individual patient's regression of FEV1 per cent predicted versus age, such as the slope and the intercept or true value of FEV1 per cent predicted at a given age. We also illustrate how the model provides empirical Bayes estimates of these individual parameters. In particular, we explore how the predicted value of the age at death might be used as a prognostic or severity index. The model and methods are illustrated on a cohort of 188 cystic fibrosis patients with a common genotype (homozygous for the DeltaF508 mutation), born on or after 1965 and followed at the CF Center at the Rainbow Babies and Children's Hospital, Cleveland, OH, U.S.A. Copyright (C) 2002 John Wiley Sons, Ltd.