To determine the time-varying associations between 1) decreased handgrip strength and disabilities in each activity of daily living (ADL) function, and 2) disaggregated ADL limitations and time to mortality in older adults.
A United States nationally representative sample of 17,747 older adults from the Health and Retirement Study were followed up for 8 yr. Maximal handgrip strength was measured with a hand-held dynamometer. Ability to perform ADL was self-reported. Date of death was identified by the National Death Index and exit interviews. Separate covariate-adjusted hierarchical logit models were used to examine the time-varying associations between decreased handgrip strength and each ADL outcome. Distinct covariate-adjusted Cox models were used to analyze the time-varying associations between disaggregated ADL limitations and time to mortality.
Every 5-kg decrease in handgrip strength was associated with increased odds for the following ADL limitations: 20% for eating, 14% for walking, 14% for bathing, 9% for dressing, 8% for transferring, and 6% for toileting. The presence of a bathing, walking, toileting, eating, and dressing ADL disability was associated with a 47%, 43%, 32%, 30%, and 19% higher hazard for mortality, respectively. A transferring ADL disability was not significantly associated with mortality.
Decreased handgrip strength was associated with increased odds for each ADL limitation, and in turn, most individual ADL impairments were associated with a higher hazard for mortality in older adults. These findings provide insights into the disabling process by identifying which ADL limitations are most impacted by decreased handgrip strength and the subsequent time to mortality for each ADL disability.
1Department of Health, Nutrition, and Exercise Sciences, North Dakota State University, Fargo, ND;
2Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI;
3Center for Clinical Management Research, VA Ann Arbor Healthcare System, Ann Arbor, MI;
4Division of Preventive Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA;
5Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA; and
6Department of Human Sciences, The Ohio State University, Columbus, OH
Address for correspondence: Ryan McGrath, Ph.D., Department of Health, Nutrition, and Exercise Sciences, North Dakota State University, NDSU Dept. 2620, PO Box 6050, Fargo, ND 58108-6050; E-mail: firstname.lastname@example.org.
Submitted for publication February 2018.
Accepted for publication May 2018.
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