Kharroubi Samer A, Edlin Richard, Meads David, McCabe Christopher
Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon.
School of Population Health, University of Auckland, Auckland, New Zealand.
Pharm Stat. 2018 Jul;17(4):358-371. doi: 10.1002/pst.1853. Epub 2018 Feb 20.
It is well documented that the modelling of health-related quality of life data is difficult as the distribution of such data is often strongly right/left skewed and it includes a significant percentage of observations at one. The objective of this study is to develop a series of two-part models (TPMs) that deal with these issues. Data from the UK Medical Research Council Myeloma IX trial were used to examine the relationship between the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30/QLQ-MY20 scores and the European QoL-5 Dimensions (EQ-5D) utility score. Four different TPMs were developed. The models fitted included TPM with normal regression, TPM with normal regression with variance a function of participant characteristics, TPM with log-transformed data, and TPM with gamma regression and a log link. The cohort of 1839 patients was divided into 75% derivation sample, to fit the different models, and 25% validation sample to assess the predictive ability of these models by comparing predicted and observed mean EQ-5D scores in the validation set, unadjusted R , and root mean square error. Predictive performance in the derivation dataset depended on the criterion used, with R /adjusted-R favouring the TPM with normal regression and mean predicted error favouring the TPM with gamma regression. The TPM with gamma regression performs best within the validation dataset under all criteria. TPM regression models provide flexible approaches to estimate mean EQ-5D utility weights from the EORTC QLQ-C30/QLQ-MY20 for use in economic evaluation.
有充分文献记载，与健康相关的生活质量数据建模很困难，因为此类数据的分布往往严重右偏/左偏，且包含相当比例的零值观测。本研究的目的是开发一系列两部分模型（TPM）来处理这些问题。使用来自英国医学研究理事会骨髓瘤IX试验的数据，来检验欧洲癌症研究与治疗组织（EORTC）QLQ-C30/QLQ-MY20评分与欧洲生活质量五维度（EQ-5D）效用评分之间的关系。开发了四种不同的TPM。拟合的模型包括具有正态回归的TPM、具有正态回归且方差为参与者特征函数的TPM、具有对数变换数据的TPM，以及具有伽马回归和对数链接的TPM。1839名患者的队列被分为75%的推导样本以拟合不同模型，以及25%的验证样本，通过比较验证集中预测和观察到的平均EQ-5D评分、未调整的R²和均方根误差来评估这些模型的预测能力。推导数据集中的预测性能取决于所使用的标准，R²/调整后的R²有利于具有正态回归的TPM，而平均预测误差有利于具有伽马回归的TPM。在所有标准下，具有伽马回归的TPM在验证数据集中表现最佳。TPM回归模型提供了灵活的方法，可从EORTC QLQ-C30/QLQ-MY20估计平均EQ-5D效用权重，用于经济评估。
