Öhlin J1, Ahlgren A1, Folkesson R1, Gustafson Y1, Littbrand H1, Olofsson B2, Toots A1
1Umeå University, Department of Community Medicine and Rehabilitation, Umeå, Sweden, 2Umeå University, Department of Nursing, Umeå, Sweden
Background: An association between cognition and gait speed has been shown amongst ambulant older people. However, very old people over 80 years, people with dementia, and people living in residential care are often excluded from studies. Gait deficits, cognitive impairment, medical conditions, and use of walking aids are frequent in such groups of the older population, which may influence interpretation.
Purpose: To investigate the association between cognitive function and gait speed in a representative sample of very old people, including people with dementia and in residential care, and whether the association is affected by walking aid use.
Methods: In a population-based cohort study, set in urban and rural parts of northern Sweden and Finland (the Umeå 85+/GERDA study), people aged 85-, 90-, and 95 years or older were invited. Interviews and assessments, including the Mini-Mental State Examination (MMSE) and usual gait speed over 2.4 meter, took place in participants' homes. Individuals who completed the MMSE were included. The association between gait speed and cognition was analysed using multiple linear regression, adjusted for possible confounders, and stratified according to dementia. The influence of missing gait speed values was explored using multiple imputation. An interaction analysis was performed to investigate differences in the association depending on walking aid use.
Results: In total 1317 participants were included, with a mean age of 89.4 years, 68% female. Four-hundred-sixty-four (35%) participants had dementia, and 1030(78%) completed the gait speed test, of who 321(31%) used walking aid. A positive association was found between global cognitive function and gait speed in the total sample (unstandardized beta [β]=0.011, 95% Confidence Intervals [CI]=0.009, 0.013, p 0.001). In participants with dementia, while MMSE was not associated with gait speed in participants with measured gait speed (β=0.003, 95%CI=0.000, 0.006, p=0.058), when imputed values for gait speed were added, it was (β=0.007, 95%CI=0.002, 0.011, p=0.002). In interaction analyses, the association differed according to walking aid use (β=-0.005, 95%CI =-0.009, -0.000, p=0.032), and seemed stronger in those that walked without a walking aid.
Conclusion(s): In this study of very old people, including those with dementia and living in residential care, an association between global cognitive function and gait speed was shown in comprehensively adjusted analyses. Many participants unable to complete the gait speed test had dementia, which appeared to influence the association. Additionally, the use of walking aids in gait speed test seems to reduce the association between gait and cognition.
Implications: Increased knowledge of the association between gait and cognition in very old people, including those with dementia and living in residential care facilities, may improve prevention and rehabilitation of age-related disorders. Selection bias may be a problem for studies investigating gait related factors in people with dementia in particular. Whether a walking aid is used when measuring gait speed can be important for interpretation of results. In the clinical setting, when using gait speed as an indicator of physical or cognitive health, it may be advisable to test without a walking aid if possible.
Keywords: Cognition, Gait speed, Walking aid
Funding acknowledgements: The Swedish Research Council, The Swedish Dementia Foundation and Forte - Swedish Research Council for Health, Working Life and Welfare.
Purpose: To investigate the association between cognitive function and gait speed in a representative sample of very old people, including people with dementia and in residential care, and whether the association is affected by walking aid use.
Methods: In a population-based cohort study, set in urban and rural parts of northern Sweden and Finland (the Umeå 85+/GERDA study), people aged 85-, 90-, and 95 years or older were invited. Interviews and assessments, including the Mini-Mental State Examination (MMSE) and usual gait speed over 2.4 meter, took place in participants' homes. Individuals who completed the MMSE were included. The association between gait speed and cognition was analysed using multiple linear regression, adjusted for possible confounders, and stratified according to dementia. The influence of missing gait speed values was explored using multiple imputation. An interaction analysis was performed to investigate differences in the association depending on walking aid use.
Results: In total 1317 participants were included, with a mean age of 89.4 years, 68% female. Four-hundred-sixty-four (35%) participants had dementia, and 1030(78%) completed the gait speed test, of who 321(31%) used walking aid. A positive association was found between global cognitive function and gait speed in the total sample (unstandardized beta [β]=0.011, 95% Confidence Intervals [CI]=0.009, 0.013, p 0.001). In participants with dementia, while MMSE was not associated with gait speed in participants with measured gait speed (β=0.003, 95%CI=0.000, 0.006, p=0.058), when imputed values for gait speed were added, it was (β=0.007, 95%CI=0.002, 0.011, p=0.002). In interaction analyses, the association differed according to walking aid use (β=-0.005, 95%CI =-0.009, -0.000, p=0.032), and seemed stronger in those that walked without a walking aid.
Conclusion(s): In this study of very old people, including those with dementia and living in residential care, an association between global cognitive function and gait speed was shown in comprehensively adjusted analyses. Many participants unable to complete the gait speed test had dementia, which appeared to influence the association. Additionally, the use of walking aids in gait speed test seems to reduce the association between gait and cognition.
Implications: Increased knowledge of the association between gait and cognition in very old people, including those with dementia and living in residential care facilities, may improve prevention and rehabilitation of age-related disorders. Selection bias may be a problem for studies investigating gait related factors in people with dementia in particular. Whether a walking aid is used when measuring gait speed can be important for interpretation of results. In the clinical setting, when using gait speed as an indicator of physical or cognitive health, it may be advisable to test without a walking aid if possible.
Keywords: Cognition, Gait speed, Walking aid
Funding acknowledgements: The Swedish Research Council, The Swedish Dementia Foundation and Forte - Swedish Research Council for Health, Working Life and Welfare.
Topic: Older people
Ethics approval required: Yes
Institution: Umeå University
Ethics committee: Regional Ethics Review Board in Umeå
Ethics number: 2018-188-32M
All authors, affiliations and abstracts have been published as submitted.
