Physical Functioning Decline and Mortality in Older Adults with Multimorbidity: Joint Modeling of Longitudinal and Survival Data.

TitlePhysical Functioning Decline and Mortality in Older Adults with Multimorbidity: Joint Modeling of Longitudinal and Survival Data.
Publication TypeJournal Article
Year of Publication2019
AuthorsWei, MY, Kabeto, MU, Galecki, AT, Langa, KM
JournalJournals of Gerontology Series A: Biological Sciences & Medical Sciences
Volume74
Issue2
Pagination226-232
ISSN Number1758-535X
KeywordsComorbidity, Mortality, Physical Ability
Abstract

Background: Multimorbidity is common among older adults and strongly associated with physical functioning decline and increased mortality. However, the full spectrum of direct and indirect effects of multimorbidity on physical functioning and survival has not been quantified. We aimed to determine the longitudinal relationship of multimorbidity on physical functioning and quantify the impact of multimorbidity and multimorbidity-attributed changes in physical functioning on mortality risk.

Methods: The Health and Retirement Study is a nationally-representative population-based prospective cohort of adults aged 51 or older. In 2000, participants were interviewed about physician-diagnosed chronic conditions, from which their multimorbidity-weighted index (MWI) was computed. Between 2000-2011, participants reported their current physical functioning using a modified Short Form-36. With MWI as a time-varying exposure, we jointly modeled its associations with physical functioning and survival.

Results: The final sample included 74,037 observations from 18,174 participants. At baseline, participants had a weighted mean MWI of 4.64.2 (range 0-36.8). During follow-up, physical functioning declined -1.72 (95% CI: -1.77, -1.67, p<0.001) HRS physical functioning units per point MWI in adjusted models. Over follow-up, 6,362 (34%) participants died. Mortality risk increased 8% (HR 1.08, 95% CI 1.07-1.08, p<0.001) per point MWI in adjusted models. Across all population subgroups, MWI was associated with greater physical functioning decline and mortality risk.

Conclusions: Multimorbidity and its associated decline in physical functioning were significantly associated with increased mortality. These associations can be predicted with an easily interpreted and applied multimorbidity index that can better identify and target adults at increased risk for disability and death.

DOI10.1093/gerona/gly038
User Guide Notes

http://www.ncbi.nlm.nih.gov/pubmed/29529179?dopt=Abstract

Alternate JournalJ. Gerontol. A Biol. Sci. Med. Sci.
Citation Key9548
PubMed ID29529179