Accelerometer-Measured Daily Steps, Physical Function, and Subsequent Fall Risk in Older Women: The Objective...

Area of Science:

• Gerontology
• Epidemiology
• Physical Therapy

Background:

• Falls are a major health concern for older adults, leading to injury and reduced mobility.
• Physical activity, such as daily stepping, is believed to play a role in fall prevention.

Purpose of the Study:

• To investigate the association between daily steps and incident falls in older women.
• To explore the mediating role of physical function in this relationship.

Main Methods:

• Accelerometer data collected daily steps for 7 days in 5,545 women (aged 63-97).
• Incident falls were tracked via daily fall calendars for 13 months.
• Statistical analyses included incidence rate ratios and mediation analysis, adjusting for physical function (Short Physical Performance Battery).

Main Results:

• Median daily steps were 3,216, with 5,473 falls recorded.
• Higher daily steps were associated with a lower incidence of falls (IRR=0.71).
• This association was attenuated after adjusting for physical function (IRR=0.86), with mediation analysis indicating physical function mediated 63.7% of the effect.

Conclusions:

• Increased daily steps are linked to reduced fall incidence in older women.
• Physical function significantly mediates the protective effect of stepping on falls.
• Interventions promoting physical function, including stepping, may effectively reduce fall risk in this population.