IF 1.3 3区 生物学 Q4 MATHEMATICAL & COMPUTATIONAL BIOLOGY
Mireya Díaz
{"title":"Assessing Balance of Baseline Time-Dependent Covariates via the Fréchet Distance","authors":"Mireya Díaz","doi":"10.1002/bimj.70024","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>Assessment of covariate balance is a key step when performing comparisons between groups particularly in real-world data. We generally evaluate it on baseline covariates, but rarely on longitudinal ones prior to a management decision. We could use pointwise standardized mean differences, standardized differences of slopes, or weights from the model for such purpose. Pointwise differences could be cumbersome for densely sampled longitudinal markers and/or measured at different points. Slopes are suitable for linear or transformable models but not for more complex curves. Weights do not identify the specific covariate(s) responsible for imbalances. This work presents the Fréchet distance as a viable alternative to assess balance of time-dependent covariates. A set of linear and nonlinear curves for which their standardized difference or differences in functional parameters were within 10% sought to identify the Fréchet distance equivalent to this threshold. This threshold is dependent on the level of noise present and thus within group heterogeneity and error variance are needed for its interpretation. Applied to a set of real curves representing the monthly trajectory of hemoglobin A1c from diabetic patients showed that the curves in the two groups were not balanced at the 10% mark. A Beta distribution represents the Fréchet distance distribution reasonably well in most scenarios. This assessment of covariate balance provides the following advantages: It can handle curves of different lengths, shapes, and arbitrary time points. Future work includes examining the utility of this measure under within-series missingness, within-group heterogeneity, its comparison with other approaches, and asymptotics.</p>\n </div>","PeriodicalId":55360,"journal":{"name":"Biometrical Journal","volume":"67 1","pages":""},"PeriodicalIF":1.3000,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biometrical Journal","FirstCategoryId":"99","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/bimj.70024","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATHEMATICAL & COMPUTATIONAL BIOLOGY","Score":null,"Total":0}
引用次数: 0

摘要

在进行组间比较时,尤其是在实际数据中,评估协变量平衡是一个关键步骤。我们通常对基线协变量进行评估,但很少在管理决策前对纵向协变量进行评估。为此,我们可以使用标准化均值点差、标准化斜率差或模型权重。对于取样密集的纵向标记和/或在不同点测量的标记,点平均差可能比较麻烦。斜率适用于线性或可转换模型,但不适用于更复杂的曲线。权重不能确定造成不平衡的具体协变量。这项工作提出了弗雷谢特距离,作为评估随时间变化的协变量平衡的可行替代方法。一组线性和非线性曲线的标准化差异或功能参数差异在 10%以内,我们试图找出与这一阈值相当的弗雷谢特距离。该阈值取决于存在的噪声水平,因此在解释时需要考虑组内异质性和误差方差。对一组代表糖尿病患者血红蛋白 A1c 每月变化轨迹的真实曲线进行应用后发现,两组的曲线在 10%的界限处并不平衡。Beta 分布在大多数情况下都能很好地代表弗雷谢特距离分布。这种协变量平衡评估具有以下优点:它可以处理不同长度、形状和任意时间点的曲线。未来的工作包括研究这种测量方法在序列内缺失、组内异质性、与其他方法的比较以及渐近性等情况下的实用性。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Assessing Balance of Baseline Time-Dependent Covariates via the Fréchet Distance

Assessment of covariate balance is a key step when performing comparisons between groups particularly in real-world data. We generally evaluate it on baseline covariates, but rarely on longitudinal ones prior to a management decision. We could use pointwise standardized mean differences, standardized differences of slopes, or weights from the model for such purpose. Pointwise differences could be cumbersome for densely sampled longitudinal markers and/or measured at different points. Slopes are suitable for linear or transformable models but not for more complex curves. Weights do not identify the specific covariate(s) responsible for imbalances. This work presents the Fréchet distance as a viable alternative to assess balance of time-dependent covariates. A set of linear and nonlinear curves for which their standardized difference or differences in functional parameters were within 10% sought to identify the Fréchet distance equivalent to this threshold. This threshold is dependent on the level of noise present and thus within group heterogeneity and error variance are needed for its interpretation. Applied to a set of real curves representing the monthly trajectory of hemoglobin A1c from diabetic patients showed that the curves in the two groups were not balanced at the 10% mark. A Beta distribution represents the Fréchet distance distribution reasonably well in most scenarios. This assessment of covariate balance provides the following advantages: It can handle curves of different lengths, shapes, and arbitrary time points. Future work includes examining the utility of this measure under within-series missingness, within-group heterogeneity, its comparison with other approaches, and asymptotics.

求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
Biometrical Journal
Biometrical Journal 生物-数学与计算生物学
CiteScore
3.20
自引率
5.90%
发文量
119
审稿时长
6-12 weeks
期刊介绍: Biometrical Journal publishes papers on statistical methods and their applications in life sciences including medicine, environmental sciences and agriculture. Methodological developments should be motivated by an interesting and relevant problem from these areas. Ideally the manuscript should include a description of the problem and a section detailing the application of the new methodology to the problem. Case studies, review articles and letters to the editors are also welcome. Papers containing only extensive mathematical theory are not suitable for publication in Biometrical Journal.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信