Multimorbidity, the coexistence of multiple chronic conditions, poses a major and growing challenge to aging adults, their families, and healthcare systems. Most older adults have multiple chronic conditions that interact to profoundly affect physical functioning and health-related quality of life. Despite this, critical gaps remain in the measurement of multimorbidity. In particular, there are few practical tools to guide clinicians, researchers, and policymakers who seek to improve the care for older adults. Current measures for multimorbidity have used mortality, healthcare cost, and utilization, but have not focused on patient-centered outcomes to quantify burden of disease. Statistical limitations in traditional methods to measure disease interactions beyond simple two-way disease interactions have also hampered our epidemiologic understanding of multimorbidity and its full impact on health and functional outcomes. To bridge these gaps, this proposal aims to 1) Develop and validate a new multimorbidity index for use in ICD-coded conditions; 2) Refine the multimorbidity index by incorporating multiple-order disease interactions and determine the incremental value of their inclusion; and 3) Assess the utility of the multimorbidity index through its association with key functional outcomes including physical and cognitive performance, basic and instrumental activities of daily living, depression, and mortality. The proposed studies will use unique data linkages between patient-reported outcomes in the nationally- representative Health and Retirement Study and Medicare claims to develop and internally validate a multimorbidity index for International Classification of Diseases (ICD)-coded chronic conditions weighted to physical functioning. Novel approaches to data shrinkage techniques will be used to select significant interactions among multiple potential disease combinations associated with physical functioning. The utility of the multimorbidity index will be assessed through its prospective associations with physical and cognitive performance, basic and instrumental activities of daily living, and mortality. The successful completion of these studies will yield a validated multimorbidity measure that captures the impact of coexisting chronic diseases on physical functioning in older adults relevant for clinical care, research, and policy. Through this award, the candidate will achieve immediate career goals to gain new specialized skills in using administrative claims, ICD coded data, and novel statistical approaches to high-dimension data, and achieve a deeper understanding of measuring key health outcomes in older adults with multimorbidity. The facilities, sponsoring department, and intellectual resources at the University of Michigan provide an exceptional milieu for this career development award and Early Stage Investigator. The training and professional development acquired through this award will contribute to the candidate's long-term goal to be an independent clinician- investigator focused on improving the management, quality of care, and prognosis of vulnerable older adults with multimorbidity.

Public Health Relevance

Multimorbidity poses a major and growing challenge to aging adults, their families, and healthcare systems, yet current measures for multimorbidity fail to capture the diversity, severity, and synergy among diseases using patient-reported outcomes. A more robust measure of multimorbidity that captures the impact of multiple coexisting chronic diseases on physical functioning in older adults is crucial for clinical care, research, and health policy. This research will produce an improved multimorbidity tool that may be used to help guide and improve the management, quality of care, and prognosis of older adults with multimorbidity.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Mentored Patient-Oriented Research Career Development Award (K23)
Project #
5K23AG056638-04
Application #
9925770
Study Section
Behavior and Social Science of Aging Review Committee (NIA)
Program Officer
Salive, Marcel
Project Start
2017-09-15
Project End
2022-05-31
Budget Start
2020-06-01
Budget End
2021-05-31
Support Year
4
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Wei, Melissa Y; Mukamal, Kenneth J (2018) Multimorbidity and Mental Health-Related Quality of Life and Risk of Completed Suicide. J Am Geriatr Soc :
Wei, Melissa Y; Kabeto, Mohammed U; Galecki, Andrzej T et al. (2018) Physical Functioning Decline and Mortality in Older Adults with Multimorbidity: Joint Modeling of Longitudinal and Survival Data. J Gerontol A Biol Sci Med Sci :