STATISTICAL CORE

统计核心将确保在各个项目中收集统一、准确和完整的数据。核心将对项目1-3的主要目标进行初步分析，并应用程序调查各项目成果的一致性。清理后的数据集将提供给调查人员进行二次分析，并最终供公众使用。核心股将负责调查员、内部指导委员会和咨询委员会及时收到关于研究进展和调查结果的报告。核心将与新的统计发展保持同步，并为统计问题的调查人员提供资源。 统计分析将使用回归方法，根据人口特征有条件地将一种工具的分数转换为另一种工具的分数。这些翻译将在各个项目中进行验证。分层模型将用于纵向分析，检查治疗反应的时间趋势，并将强调均值和方差结构。核心还将应用结构方程模型来汇集不同指标的数据，并研究健康指标与健康和HRQOL潜在维度的联合关系所有分析将包括仔细检查模型适用性和检查缺失数据引入的潜在偏差。

The Statistics Core will ensure that uniform, accurate and complete data are collected across projects. The Core will perform primary analyses for key aims in Projects 1-3 and apply procedures to investigate consistency of results across projects. Cleaned data sets will be provided to investigators for secondary analyses and eventually for use by the public. The Core unit will take responsibility for investigators, internal Steering Committee, and the Advisory Board receiving timely reports on study progress and findings. The core will stay abreast new statistical developments and serve as a resource to investigators on statistical issues. Statistical analyses will use regression methods for translating scores from one instrument into another conditionally on population characteristics. These translations will be validated across projects. Hierarchical models will be used for longitudinal analyses examining time trends in response to treatment, and will emphasize both mean and variance structure. The Core will also apply structural equations models to pool data across measures, and study the joint relationships of health measures on latent dimensions of health and HRQOL All analyses will include careful checking of model fit and examination of potential biases introduced by missing data.