Statistical Methods for Ordinal Variables in HIV/AIDS Studies

HIV/AIDS 研究中顺序变量的统计方法

• 批准号: 8264736
• 负责人: Bryan Earl Shepherd
• 金额: $ 39万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-18 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8264736
• 关键词: AIDS/HIV problem; Accounting; Address; Adolescent; Anti-Retroviral Agents; Bacterial Vaginosis; Categories; Cervical; Clinical; Collaborations; Communities; Computer software; Data; Data Analyses; Diagnostic; Disease; Educational Background; Ensure; Evaluation; Event; Failure; Felis catus; Female Adolescents; Frequencies; Genetic; Genetic Polymorphism; Genotype; HIV; Human Genetics; Lead; Lesion; Linear Models; Measurement; Measures; Methods; Modeling; Nature; Outcome; Patient Self-Report; Patients; Pattern; Pharmaceutical Preparations; Plasma; Property; Regimen; Research Personnel; Residual state; Scientist; Sexually Transmitted Diseases; Simulate; Staging; Statistical Methods; Statistical Models; Structural Models; Techniques; Testing; Time; Toxic effect; Vaginal Douching; Work; abacavir; base; cohort; condoms; efavirenz; innovation; interest; novel; prospective; public health relevance; response; statistics; success; tool; user friendly software

DESCRIPTION (provided by applicant): Many important variables in biomedical studies of HIV/AIDS are ordered categorical. A few examples include WHO clinical stage, level of education, frequency of douching, stage of cervical lesions, self- reported condom use, and biallelic genotypes. Although ordinal variables are common, statistical methods that account for their ordered nature are lacking, particularly when the ordinal variable is a predictor variable. Most standard methods either treat the ordinal predictor as categorical (ignoring the order information) or continuous (making linearity assumptions). This proposal develops statistical methods that account for the ordered nature of ordinal variables without making linearity assumptions. The methods address situations when a predictor variable (X) is ordered categorical; the outcome variable (Y) is continuous, discrete, counts, time-to-event, or repeated measures; and there are multiple covariates (Z). The general approach is to fit appropriate regression models of Y on Z, and X on Z, and then to test for correlation between the residuals from these two models. The methods therefore rely on a new definition of residual for ordered categorical data. Statistical properties of this residual are evaluated, as well as its use in model diagnostics. Asymptotic properties of the residual- based test statistics are computed, relationships with other methods are derived, user-friendly software that implements these methods is developed, and the advantages of the new methods are studied using simulated and real data. The methods are applied to two HIV studies: The first assesses the effect of the frequency of douching on sexually transmitted infections among a cohort of adolescent females using marginal structural models. The second data application looks for human genetic polymorphisms associated with drug plasma levels, virologic failure, and toxicities for patients initiating an efavirenz- or abacavir-based antiretroviral regimen. PUBLIC HEALTH RELEVANCE: The new methods are put into computer software and applied to studies of 1) the effect of douching on sexually transmitted infections among adolescent females, and 2) which patients may be able to better respond to specific HIV-treatments based on genetic patterns.

描述（由申请人提供）：艾滋病毒/艾滋病生物医学研究中的许多重要变量被分类。一些例子包括谁临床阶段，教育水平，灌注频率，颈椎病变的阶段，自我报告的避孕套使用和双重基因型。尽管序数变量很常见，但缺乏解释其有序性质的统计方法，尤其是当序变量是预测变量时。大多数标准方法要么将序数预测器视为分类（忽略订单信息）或连续（使线性假设）。该建议开发了统计方法，这些方法可以说明序数变量的有序性质而不做出线性假设。当预测变量（x）被分类时，方法解决情况；结果变量（y）是连续的，离散的，计数，事件时间或重复的度量；并且有多个协变量（z）。一般方法是拟合Z上Y的适当回归模型，然后在Z上x x，然后测试这两个模型的残差之间的相关性。因此，这些方法依赖于有序分类数据的残差的新定义。评估了该残差的统计特性及其在模型诊断中的使用。计算了基于残差的测试统计数据的渐近性能，与其他方法的关系得出，用户友好的软件可以开发这些方法，并使用模拟和真实数据研究了新方法的优势。该方法应用于两项HIV研究：第一个评估了使用边际结构模型在青少年女性中进行性传播感染的频率对性传播感染的影响。第二个数据应用程序寻找与药物血浆水平，病毒学衰竭和毒性相关的人类遗传多态性，用于启动基于efavirenz或abacavir的抗逆转录病毒方案的患者。 公共卫生相关性：将新方法纳入计算机软件中，并应用于1）对青少年女性进行性传播感染的影响，以及2）患者可能能够根据遗传模式更​​好地对特定的HIV治疗做出反应。