Association of mobility limitations with incident disability among older adults: a population-based study

Abstract

Background: mobility-related limitations predict future disability; however, the extent to which individual and combined mobility tests may predict disability remains unclear.

Objectives: to estimate the odds of developing disability in activities of daily living (ADL) according to limitations in walking speed, balance or both; and explore the role of chronic diseases and cognitive function.

Design: a prospective cohort study.

Setting: urban area of Stockholm, Sweden.

Subjects: one thousand nine hundred and seventy-one disability-free persons (age ≥60 years, 63% women) from the Swedish National study on Aging and Care in Kungsholmen (SNAC-K), who underwent baseline examination in 2001-04 and follow-up assessments for 6 years.

Measurements: mobility limitation was defined as a one-leg balance stand <5 s or walking speed <0.8 m/s. ADL disability was defined as the inability to complete one or more ADL: bathing, dressing, using the toilet, transferring and eating.

Results: during a total of 11,404 person-years (mean per person 5.8 years, SD 0.30) of follow-up, 119 (incidence 1.5/100 person-years) participants developed ADL disability. The demographic adjusted odds ratios (OR) (95% confidence intervals, CI) of incident ADL disability related to balance stand and walking speed limitations were 3.8 (2.3-6.3) and 8.4 (5.2-13.3), respectively. The associations remained statistically significant after controlling for number of chronic diseases and cognitive status. People with limitations in both balance and walking speed had an OR of 12.9 (95% CI 7.0-23.7) for incident disability compared with no limitation.

Conclusion: balance and walking speed tests are simple clinical procedures that can indicate hierarchical risk of ADL dependence in older adults.

Keywords: activities of daily living; chronic disease; cognitive function; disability; older people; physical performance.