Creating a better index for measuring multimorbidity in older adults

背景：多种慢性病(多发病)的存在对健康有深远的影响 以及老年人的医疗保健。因此，对老年人的流行病学和临床研究取决于 能够以准确和概念上有效的方式测量多发性疾病。然而，现有的方法 衡量多发病有很大的差距。使用常用数据的大多数现有衡量标准 来源只包括预测住院和死亡的疾病。这些方法不适合测量 多发性疾病的其他方面，包括对老年人在日常生活中独立运作能力的影响 -对这一人口至关重要的结果。庞大且不断增长的研究和临床机构 因此，注重功能结果的方案缺乏适当的工具来解决多发病问题。创新型 使用索赔数据很有希望开发新的多发病测量方法，重点关注其对 功能结果。此外，这些方法提供了一个独特的机会来改进现有的 关注住院和死亡等“传统”结果的多发病衡量标准。 目标：(1)开发和验证基于索赔的多发病测量方法，以预测能力下降 进行日常生活的基本和工具性活动(ADL、IADL)；(2)使用更广泛的疾病 索赔数据中可测量的特征，以开发和验证预测多发病的措施 住院和死亡；(3)比较我们测量的功能衰退的预测有效性， 住院和死亡与查尔逊指数等现有的多发病指标相一致。 方法：使用与健康和退休中心的自我报告ADL和IADL数据链接的联邦医疗保险索赔数据 研究中，我们将使用预后模型开发的框架来构建4个多发病指数。每个人 将开发指数来预测与多发病有关的单独结果，包括能力下降 执行ADL(如洗澡)、执行IADL能力下降(如购物)、住院和死亡。 这些模型中的预测因素将是可以在索赔数据中衡量的疾病特征，包括 疾病，疾病严重程度的标志，以及疾病与疾病的相互作用。这些预测模型将是 转换成简单的指数，其中每个疾病特征将被分配一些分数，并且 这些分数的总和将给出患者水平的多病评分。我们将使用以下工具内部验证我们的索引 引导技术，并在美国国家卫生与公众服务局的一群老年人中进行外部验证 老龄化趋势研究。在整个过程中，我们将咨询一组专家顾问，以确保我们 以对研究人员和卫生系统领导者最有用的方式制定我们的措施。 相关性/公共卫生意义：改进了反映以患者为中心的多发性疾病的衡量标准 结果将是临床流行病学、卫生服务研究和临床方案的关键工具 寻求改善对老年人的护理。

Background: The presence of multiple chronic conditions (multimorbidity) has profound impacts on the health and health care of older adults. As a result, epidemiologic and clinical research on older adults depends on being able to measure multimorbidity in an accurate and conceptually valid manner. Yet, existing methods of measuring multimorbidity have critical gaps. Most existing measures that use commonly-available data sources include only diseases that predict hospitalization and death. These methods are ill-suited to measure other aspects of multimorbidity, including its impact on older adults' ability to function independently in daily life – an outcome of vital importance to this population. The large and growing body of research and clinical programs that focus on functional outcomes thus lack the proper tools to address multimorbidity. Innovative uses of claims data hold great promise to develop new measures of multimorbidity focused on its impact on functional outcomes. Moreover, these approaches offer a unique opportunity to improve upon existing multimorbidity measures that focus on “traditional” outcomes such as hospitalization and death. Aims: (1) To develop and validate claims-based measures of multimorbidity that predict decline in ability to perform basic and instrumental activities of daily living (ADLs, IADLs); (2) Using an expanded range of disease characteristics measurable in claims data, to develop and validate measures of multimorbidity that predict hospitalization and death; (3) To compare the predictive validity of our measures for functional decline, hospitalization, and death with existing measures of multimorbidity such as the Charlson Index. Methods: Using Medicare claims data linked to self-report ADL and IADL data from the Health and Retirement Study, we will build 4 indices of multimorbidity using the framework of prognostic model development. Each index will be developed to predict a separate outcome related to multimorbidity, including decline in ability to perform ADLs (e.g. bathing), decline in ability to perform IADLs (e.g. shopping), hospitalization, and death. Predictors in these models will be disease characteristics that can be measured in claims data including diseases, markers of disease severity, and disease-disease interactions. These prognostic models will be converted into simple indices, where each disease characteristic will be assigned a number of points, and the sum of these points will give a patient-level multimorbidity score. We will internally validate our indices using bootstrapping techniques, and externally validate them in a cohort of older adults from the National Health and Aging Trends Study. Throughout this process, we will consult with a group of expert advisors to ensure that we develop our measures in a manner that is maximally useful to researchers and health systems leaders. Relevance / public health significance: Improved measures of multimorbidity that reflect patient-centered outcomes will be crucial tools for clinical epidemiology, health services research, and clinical programs that seek to improve care for older adults.