Biostatistical methods in epidemiology

申请者的工作包括与临床和人口流行病学家合作研究，以及开发相关的生物统计学方法。拟议的工作将在三个主要领域进行：(1)诊断和筛查测试的评估；(2)流行病学中常用的效果衡量标准的性质；(3)临床试验的设计和分析。领域1：需要考虑的具体问题包括：使用不完善的参考标准进行测试评估；诊断和筛查研究的荟萃分析；总结ROC曲线的性质；以及扩展潜在类别模型以涵盖诊断标记物中的不确定性。区域2：将调查两种影响措施(NNT和PAR)。NNT(需要治疗的人数)指数反映了从治疗干预中受益的患者的相对数量。在需要调查的各种统计问题中，有一项是在考虑到干预的危害和益处的价值的情况下，估算NNT的阈值。一个相关的重点将是在存在关于暴露和/或疾病状况的不完善数据的情况下，PAR(人口归因风险)估计的行为。领域3：申请人将致力于两种新方法的基本性质-基于专业知识的临床试验和基于偏好的试验数据分析。还将继续研究治疗盲法程序的验证，以及基线变量中测量误差造成的偏差。

The applicant's work involves collaborative research with clinical and population epidemiologists, and development of related biostatistical methodology. The proposed work will be in three main areas: (1) evaluation of diagnostic and screening tests; (2) properties of effect measures commonly used in epidemiology; and (3) design and analysis of clinical trials. Area 1: Specific issues to be considered include: test evaluation with an imperfect reference standard; meta-analysis of diagnostic and screening studies; properties of the summary ROC curve; and extension of latent class models to cover uncertainty in diagnostic markers. Area 2: Two effect measures (NNT and PAR) will be investigated. The NNT  (Number Needed to Treat) index reflects the relative number of patients who benefit from a therapeutic intervention. Among various statistical issues to be investigated is the estimation of a threshold value for NNT, taking into account the values of both harms and benefits of the intervention.  A related focus will be the behaviour of PAR (population attributable risk) estimates in the presence of imperfect data on exposure and/or disease status. Area 3: The applicant will work on basic properties of two new methods - the expertise-based clinical trial, and preference-based analysis of trial data. Research on the verification of treatment blinding procedures, and bias from measurement error in baseline variables will also continue.