The role of sensory and cognitive function in the onset of activity restriction in older people

Abstract

Background: Extending healthy active life expectancy is a priority if we are to achieve gains in both the quality and quantity of life lived at older ages. We investigated the role of sensory (vision and hearing) and cognitive function on the onset of activity restriction in older people.

Methods: A survey of a total population (N = 1579) of people aged 75 years and older, registered with a large general population in Melton Mowbray, Leicestershire, England, was undertaken in 1988 and linked with subsequent routine health assessments (up to a maximum of five) over 10 years. Activity restriction was defined as having difficulty performing on their own, requiring help or aids or not doing any one of seven Activities of Daily Living (ADLs). The study population comprised the 643 persons who were not restricted at baseline. Cox proportional hazard regression models were fitted to time of onset of activity restriction with those dying before activity restriction was reported being censored at time of death.

Results: After adjustment for confounding factors (socio-demographic and psychosocial factors, physical health and physical functional limitations), difficulty with both vision and hearing conferred a doubling of risk of activity restriction (RR = 2.36, 95% CI 1.31 to 4.28). A unit decrease in the Information/Orientation subtest was associated with a 10% increase in risk (RR = 1.10, 95% CI 1.02 to 1.19), even after adjustment for vision and hearing as well as other confounding factors, though baseline Mini-Mental State Examination score was not indicative of increased risk (RR = 1.02, 95% CI 0.98 to 1.06).

Conclusion: Differentiating whether disability is a result of physical, sensory or cognitive functional limitations, is necessary to identify need and the direction in which efforts should be targeted to improve active life expectancy in older people.